diff --git a/docs/code/Boletin_4/Ejercicio_08.c b/docs/code/Boletin_4/Ejercicio_08.c
new file mode 100644
index 0000000..56d7631
--- /dev/null
+++ b/docs/code/Boletin_4/Ejercicio_08.c
@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 10
+
+int main(){
+    // Define variables and ask for parameters
+    int nums[N], guess, lGuess, uGuess;
+    printf("\nInput an array of 10 elements by pressing Enter after each element: ");
+    for(int i=0; i<10; i++){
+        scanf("%d", &nums[i]);
+    }
+    // Input guess
+    printf("\nWhat number do you want to find?: ");
+    scanf("%d", &guess);
+    // Lower bound
+    for(int i=0; i<N; i++){
+        if(nums[i] == guess){
+            lGuess = i;
+            break;
+        }
+    }
+    // Upper bound
+    for(int i=N; i>=0; i--){
+        if(nums[i] == guess){
+            uGuess = i;
+            break;
+        }
+    }
+    // Print solutions
+    printf("\nLower bound solution: %d", lGuess);
+    printf("\nUpper bound solution: %d", uGuess);
+    printf("\n");
+}
\ No newline at end of file
diff --git a/docs/code/Boletin_4/Ejercicio_11.c b/docs/code/Boletin_4/Ejercicio_11.c
new file mode 100644
index 0000000..b1c4770
--- /dev/null
+++ b/docs/code/Boletin_4/Ejercicio_11.c
@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+
+// Sum all the elements of the array using recursion
+int arraySum(int n, int sumNums[n], int loops, int accum){
+    if (loops == 0){return accum;} else{
+        accum+=sumNums[n-loops];
+        loops--;
+        arraySum(n, sumNums, loops, accum);
+    }
+}
+
+int main(){
+    // Define variables and ask for parameters
+    int n = 10;
+    int toSum[n], accum = 0, loops = n;
+    int result;
+    printf("Input the 10 numbers for the array separated by Enter:\n");
+    for(int i=0; i<10; i++){
+        scanf("%d", &toSum[i]);
+    }
+    // Recursion fun starts here
+    result = arraySum(n, toSum, loops, accum);
+    // Print result
+    printf("\nThe result of the sum is %d\n", result);
+    return 0;
+}
\ No newline at end of file
diff --git a/docs/code/Boletin_4/Ejercicio_27.c b/docs/code/Boletin_4/Ejercicio_27.c
new file mode 100644
index 0000000..8b53f23
--- /dev/null
+++ b/docs/code/Boletin_4/Ejercicio_27.c
@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 100
+
+// Count the amount of characters in the string
+void countString(char toCount[N]){
+    int count = 0;
+    for(int i=0; toCount[i]!='\0'; i++){
+        count++;
+    }
+    printf("Word %s has %d characters\n", toCount, count);
+}
+
+// Separate the string and fix multiple separators in the string by ignoring them 
+void separateString(char toSplit[N]){
+    char splitted[N][N];
+    int count=0, row=0, column=0;
+    while(toSplit[count] != '\n'){
+        if(toSplit[count] == ' ' || toSplit[count] == ',' || toSplit[count] == '.'){
+            splitted[row][column] = '\0';
+            column = 0;
+            if (toSplit[count-1] != ' ' && toSplit[count-1] != ',' && toSplit[count-1] != '.'){row++;}
+        } else {
+            splitted[row][column] = toSplit[count];
+            column++;
+        }
+        count++;
+    }
+    for(int i=0; splitted[i][0] != '\0'; i++){
+        countString(splitted[i]);
+    }
+}
+
+int main(){
+    // Define variables and ask for parameters
+    char sentence[N];
+    printf("Type a sentence of max 100 characters:\n");
+    // fgets instead of gets for buffer overflow protection
+    fgets(sentence, N, stdin);
+    // Start the fun
+    separateString(sentence);
+    return 0;
+}
\ No newline at end of file
diff --git a/docs/code/Boletin_4/Ejercicio_28.c b/docs/code/Boletin_4/Ejercicio_28.c
new file mode 100644
index 0000000..32c3299
--- /dev/null
+++ b/docs/code/Boletin_4/Ejercicio_28.c
@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 256
+
+int main(){
+    // Define variables and ask for parameters
+    int i=0, j=0;
+    char sentence[N], fixedSentence[N];
+    printf("Type a sentence\n");
+    // fgets instead of gets for buffer protection
+    fgets(sentence, N, stdin);
+    // Fix the sentence's multiple spaces
+    while(sentence[i]!='\0'){
+        if(sentence[i] == ' ' && sentence[i+1] == ' '){
+            i++;
+            continue;
+        } else {
+            fixedSentence[j]=sentence[i];
+            i++;
+            j++;
+        }
+    }
+    // Print the result after apprending the end of string to the fixed variable
+    fixedSentence[j+1] = '\0';
+    printf("\nThe sentence with fixed spaces is:\n%s", fixedSentence);
+    return 0;
+}
\ No newline at end of file
diff --git a/docs/code/Boletin_4/Ejercicio_36.c b/docs/code/Boletin_4/Ejercicio_36.c
new file mode 100644
index 0000000..74c3b32
--- /dev/null
+++ b/docs/code/Boletin_4/Ejercicio_36.c
@@ -0,0 +1,48 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#include <stdbool.h>
+#define N 100
+
+void factorialDecomp(int toDecomp){
+    int factors[N], primes=2, loops=0, og=toDecomp;
+    // Check if its 1 or 0 and just print out that the decomp is 1
+    if(toDecomp == 0 | toDecomp == 1){
+        printf("\nNumber %d factorial decomposition is: 1", og);
+        return;
+    }
+    // Repeat the factorization with each reduced number until its 0
+    for(int i=0;i<N;i++){factors[i]=0;}
+    while(toDecomp != 1){
+        if(toDecomp%primes == 0){
+            toDecomp/=primes;
+            factors[loops]=primes;
+            loops++;
+            primes=2;
+        } else {primes++;}
+    }
+    // Print the result
+    printf("\nNumber %d factorial decomposition is: ", og);
+    for(int i=0;factors[i]!=0;i++){
+        if(factors[i+1]==0){
+            printf("%d", factors[i]);
+        } else {printf("%d*", factors[i]);}
+    }
+}
+
+int main(){
+    // Define variables and ask for parameters
+    int decompose[5];
+    printf("Type 5 integers separated by spaces:\n");
+    // Its just 5 parameters no for loop needed here
+    scanf("%d %d %d %d %d", &decompose[0], &decompose[1], &decompose[2], &decompose[3], &decompose[4]);
+    // Repeat the decomp for all numbers
+    for(int i=0;i<5;i++){
+        factorialDecomp(decompose[i]);
+    }
+    printf("\n");
+    return 0;
+}
\ No newline at end of file
diff --git a/docs/code/Boletin_4/Ejercicio_37.c b/docs/code/Boletin_4/Ejercicio_37.c
new file mode 100644
index 0000000..89dc693
--- /dev/null
+++ b/docs/code/Boletin_4/Ejercicio_37.c
@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 11
+#define M 100
+
+void checkLeaps(int n, int year){
+    int closeLeap, leaps[M], counter=1;
+    //Check closest
+    for(int i=0;i<4;i++){
+        if((year+i)%4 == 0){
+            closeLeap = year+i;
+            break;
+        }
+    }
+    // Get all the following leap years until the max amount is satisfied
+    leaps[0]=closeLeap;
+    while(counter != 100){
+        leaps[counter]=closeLeap+(4*counter);
+        counter++;
+    }
+    // Print results
+    printf("\nFollowing 100 leap years:\n");
+    for(int i=0; i<M; i++){
+        printf("%d ", leaps[i]);
+    }
+    printf("\n\n");
+}
+
+int main(){
+    // Define variables
+    char date[N];
+    int day, month, year;
+    // Endless loop so the user can change parameters (1==1)
+    while(1){
+        // Ask for parameters
+        printf("Input a date in the dd/mm/yyyy format: ");
+        scanf("%d/%d/%d", &day, &month, &year);
+        // Fix the string so it can be passed to the function more easily
+        snprintf(date, N, "%02d/%02d/%04d", day, month, year);
+        checkLeaps(100, year);
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/docs/code/Boletin_4/Ejercicio_40.c b/docs/code/Boletin_4/Ejercicio_40.c
new file mode 100644
index 0000000..f49bc08
--- /dev/null
+++ b/docs/code/Boletin_4/Ejercicio_40.c
@@ -0,0 +1,187 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h> // Main library
+#include <stdlib.h> // For managing the program
+#include <stdbool.h> // Bool function
+#include <unistd.h> // Use UNIX commands
+#include <time.h> // For random numbers
+#define N 16 // Change this number to change the matrix size
+#define SPEED 2 // Higher means faster: MUST BE GREATER OR EQUAL THAN 1
+#define clear() printf("\033[H\033[J") // Clean screen
+
+// NOTE: RUN FROM VSCODE TERMINAL OR THE MODERN WINDOWS TERMINAL APP NOT CMD OTHERWISE UTF-8 EMOJIS WILL NOT DISPLAY
+// ALSO MAKE SURE UTF-8 SUPPORT IS ENABLED IN YOUR TERMINAL OF CHOICE, APPLIES TO ALL OPERATING SYSTEMS
+
+int gameOfLife[N][N];
+int updatedGame[N][N];
+int ticks=0; // Generations
+
+// THIS IS THE MATRIX THAT WILL RUN IF THE OPTION c (choose) IS CHOSEN AT RUNTIME
+// THIS EXAMPLE MATRIX IS OF SIZE 16X16 SO IF YOU CHANGE N MODIFY THE SIZE HERE TOO
+// 0 = DISABLED, 1 = ENABLED
+int chooseGameOfLife[N][N] = {
+    {1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+    {1,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0},
+    {0,0,1,1,0,0,0,1,0,0,1,0,0,0,0,0},
+    {0,0,1,1,0,0,0,1,0,0,1,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0},
+    {0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0},
+    {0,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,1,0,0,0,1,1,0,0,0,0},
+    {0,0,1,0,0,1,0,0,0,0,1,0,1,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
+};
+
+// Make sure the cell is not outsided of the matrix
+bool outOfBound(int row, int column){
+    bool oob;
+    if(row >= N || row < 0 || column >= N || column < 0){oob = true;}
+    else {oob = false;}
+    return oob;
+}
+
+// Check rules 1, 2 and 3 for death status
+void checkDeath(int row, int column){
+    int liveNeighbours=0;
+    // Check neighbours
+    if(outOfBound(row+1,column) == false){if(gameOfLife[row+1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column+1) == false){if(gameOfLife[row+1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column-1) == false){if(gameOfLife[row+1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column) == false){if(gameOfLife[row-1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column+1) == false){if(gameOfLife[row-1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column-1) == false){if(gameOfLife[row-1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column+1) == false){if(gameOfLife[row][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column-1) == false){if(gameOfLife[row][column-1] == 1){liveNeighbours++;}}
+    // Any live cell with fewer than two live neighbours dies, as if by underpopulation.
+    if(liveNeighbours<2){updatedGame[row][column]=0;}
+    // Any live cell with two or three live neighbours lives on to the next generation.
+    else if(liveNeighbours>=2 && liveNeighbours<=3){updatedGame[row][column]=1;}
+    // Any live cell with more than three live neighbours dies, as if by overpopulation.
+    else if(liveNeighbours>3){updatedGame[row][column]=0;}
+}
+
+// Check rule 4 for revive status
+void checkRevive(int row, int column){
+    int liveNeighbours=0;
+    // Check neighbours
+    if(outOfBound(row+1,column) == false){if(gameOfLife[row+1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column+1) == false){if(gameOfLife[row+1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column-1) == false){if(gameOfLife[row+1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column) == false){if(gameOfLife[row-1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column+1) == false){if(gameOfLife[row-1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column-1) == false){if(gameOfLife[row-1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column+1) == false){if(gameOfLife[row][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column-1) == false){if(gameOfLife[row][column-1] == 1){liveNeighbours++;}}
+    // Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
+    if(liveNeighbours==3){updatedGame[row][column]=1;}
+    // Remain dead
+    else {updatedGame[row][column]=0;}
+}
+
+// Run a generation
+void tick(){
+    // Run generation
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            if(gameOfLife[i][j] == 1){checkDeath(i, j);continue;}
+            else if(gameOfLife[i][j] == 0){checkRevive(i, j);continue;}
+            else {exit(1);} // Impossible case, exit with error
+        }
+    }
+}
+
+// Show the game matrix
+void displayMatrix(){
+    printf("\n");
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            if(updatedGame[i][j] == 0){printf("⬛");}
+            if(updatedGame[i][j] == 1){printf("⬜");}            
+        }
+        printf("\n");
+    }
+    printf("Generation %d\n", ticks);
+}
+
+// Print the initial status
+void printInitial(){
+    printf("\n");
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            if(gameOfLife[i][j] == 0){printf("⬛");}
+            if(gameOfLife[i][j] == 1){printf("⬜");}
+        }
+        printf("\n");
+    }
+    printf("Initial status\n");
+}
+
+// Swap og and updated matrix
+void redoMatrix(){
+    // Put updated matrix into the original one
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            gameOfLife[i][j]=updatedGame[i][j];
+        }
+    }
+    // Set the updated matrix to 0
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            updatedGame[i][j]=0;
+        }
+    }
+}
+
+// Initial random condition
+void randCondition(){
+    srand(time(NULL));
+    // Random init
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            gameOfLife[i][j]=rand()%2;
+        }
+    }
+}
+
+int main(){
+    // Ask what to do
+    char answ;
+    while(answ != 'r' && answ != 'c'){
+        printf("Do you want a randomly generated generation or choose one? (r/c): ");
+        scanf("%c", &answ);
+        if(answ == 'r'){randCondition();}
+        else if(answ == 'c'){
+            for(int i=0; i<N; i++){
+                for(int j=0; j<N; j++){
+                    gameOfLife[i][j] = chooseGameOfLife[i][j];
+                }
+            }
+        }
+    }
+    // Start dead cells on updated
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            updatedGame[i][j]=0;
+        }
+    }
+    printInitial(); // Print initial state
+    usleep(1000000);
+    while(1){
+        clear(); // Clear screen
+        tick(); // Run generation
+        displayMatrix(); // Show the matrix
+        ticks++; // Increase counter
+        redoMatrix();
+        usleep(200000/SPEED); // Wait delay
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/src/Boletin_4/CMakeLists.txt b/src/Boletin_4/CMakeLists.txt
index c78543b..3c768f9 100644
--- a/src/Boletin_4/CMakeLists.txt
+++ b/src/Boletin_4/CMakeLists.txt
@@ -14,10 +14,10 @@ add_executable(Bol4-Ej04 Ejercicio_04.c)
 # add_executable(Bol4-Ej05 Ejercicio_05.c) 
 # add_executable(Bol4-Ej06 Ejercicio_06.c) 
 # add_executable(Bol4-Ej07 Ejercicio_07.c)
-# add_executable(Bol4-Ej08 Ejercicio_08.c)
+add_executable(Bol4-Ej08 Ejercicio_08.c)
 add_executable(Bol4-Ej09 Ejercicio_09.c)
 add_executable(Bol4-Ej10 Ejercicio_10.c)
-# add_executable(Bol4-Ej11 Ejercicio_11.c) 
+add_executable(Bol4-Ej11 Ejercicio_11.c) 
 #add_executable(Bol4-Ej12 Ejercicio_12.c) 
 #add_executable(Bol4-Ej13 Ejercicio_13.c)
 # add_executable(Bol4-Ej14 Ejercicio_14.c)
@@ -33,8 +33,8 @@ add_executable(Bol4-Ej20 Ejercicio_20.c)
 add_executable(Bol4-Ej24 Ejercicio_24.c)
 add_executable(Bol4-Ej25 Ejercicio_25.c)
 # add_executable(Bol4-Ej26 Ejercicio_26.c) 
-# add_executable(Bol4-Ej27 Ejercicio_27.c) 
-# add_executable(Bol4-Ej28 Ejercicio_28.c)
+add_executable(Bol4-Ej27 Ejercicio_27.c) 
+add_executable(Bol4-Ej28 Ejercicio_28.c)
 add_executable(Bol4-Ej29 Ejercicio_29.c)
 # add_executable(Bol4-Ej30 Ejercicio_30.c) 
 # add_executable(Bol4-Ej31 Ejercicio_31.c) 
@@ -42,8 +42,8 @@ add_executable(Bol4-Ej29 Ejercicio_29.c)
 # add_executable(Bol4-Ej33 Ejercicio_33.c) 
 # add_executable(Bol4-Ej34 Ejercicio_34.c) 
 # add_executable(Bol4-Ej35 Ejercicio_35.c)
-# add_executable(Bol4-Ej36 Ejercicio_36.c) 
-# add_executable(Bol4-Ej37 Ejercicio_37.c) 
+add_executable(Bol4-Ej36 Ejercicio_36.c) 
+add_executable(Bol4-Ej37 Ejercicio_37.c) 
 # add_executable(Bol4-Ej38 Ejercicio_38.c)
 # add_executable(Bol4-Ej39 Ejercicio_39.c) 
-# add_executable(Bol4-Ej40 Ejercicio_40.c)
+add_executable(Bol4-Ej40 Ejercicio_40.c)
diff --git a/src/Boletin_4/Ejercicio_08.c b/src/Boletin_4/Ejercicio_08.c
new file mode 100644
index 0000000..56d7631
--- /dev/null
+++ b/src/Boletin_4/Ejercicio_08.c
@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 10
+
+int main(){
+    // Define variables and ask for parameters
+    int nums[N], guess, lGuess, uGuess;
+    printf("\nInput an array of 10 elements by pressing Enter after each element: ");
+    for(int i=0; i<10; i++){
+        scanf("%d", &nums[i]);
+    }
+    // Input guess
+    printf("\nWhat number do you want to find?: ");
+    scanf("%d", &guess);
+    // Lower bound
+    for(int i=0; i<N; i++){
+        if(nums[i] == guess){
+            lGuess = i;
+            break;
+        }
+    }
+    // Upper bound
+    for(int i=N; i>=0; i--){
+        if(nums[i] == guess){
+            uGuess = i;
+            break;
+        }
+    }
+    // Print solutions
+    printf("\nLower bound solution: %d", lGuess);
+    printf("\nUpper bound solution: %d", uGuess);
+    printf("\n");
+}
\ No newline at end of file
diff --git a/src/Boletin_4/Ejercicio_11.c b/src/Boletin_4/Ejercicio_11.c
new file mode 100644
index 0000000..b1c4770
--- /dev/null
+++ b/src/Boletin_4/Ejercicio_11.c
@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+
+// Sum all the elements of the array using recursion
+int arraySum(int n, int sumNums[n], int loops, int accum){
+    if (loops == 0){return accum;} else{
+        accum+=sumNums[n-loops];
+        loops--;
+        arraySum(n, sumNums, loops, accum);
+    }
+}
+
+int main(){
+    // Define variables and ask for parameters
+    int n = 10;
+    int toSum[n], accum = 0, loops = n;
+    int result;
+    printf("Input the 10 numbers for the array separated by Enter:\n");
+    for(int i=0; i<10; i++){
+        scanf("%d", &toSum[i]);
+    }
+    // Recursion fun starts here
+    result = arraySum(n, toSum, loops, accum);
+    // Print result
+    printf("\nThe result of the sum is %d\n", result);
+    return 0;
+}
\ No newline at end of file
diff --git a/src/Boletin_4/Ejercicio_27.c b/src/Boletin_4/Ejercicio_27.c
new file mode 100644
index 0000000..8b53f23
--- /dev/null
+++ b/src/Boletin_4/Ejercicio_27.c
@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 100
+
+// Count the amount of characters in the string
+void countString(char toCount[N]){
+    int count = 0;
+    for(int i=0; toCount[i]!='\0'; i++){
+        count++;
+    }
+    printf("Word %s has %d characters\n", toCount, count);
+}
+
+// Separate the string and fix multiple separators in the string by ignoring them 
+void separateString(char toSplit[N]){
+    char splitted[N][N];
+    int count=0, row=0, column=0;
+    while(toSplit[count] != '\n'){
+        if(toSplit[count] == ' ' || toSplit[count] == ',' || toSplit[count] == '.'){
+            splitted[row][column] = '\0';
+            column = 0;
+            if (toSplit[count-1] != ' ' && toSplit[count-1] != ',' && toSplit[count-1] != '.'){row++;}
+        } else {
+            splitted[row][column] = toSplit[count];
+            column++;
+        }
+        count++;
+    }
+    for(int i=0; splitted[i][0] != '\0'; i++){
+        countString(splitted[i]);
+    }
+}
+
+int main(){
+    // Define variables and ask for parameters
+    char sentence[N];
+    printf("Type a sentence of max 100 characters:\n");
+    // fgets instead of gets for buffer overflow protection
+    fgets(sentence, N, stdin);
+    // Start the fun
+    separateString(sentence);
+    return 0;
+}
\ No newline at end of file
diff --git a/src/Boletin_4/Ejercicio_28.c b/src/Boletin_4/Ejercicio_28.c
new file mode 100644
index 0000000..32c3299
--- /dev/null
+++ b/src/Boletin_4/Ejercicio_28.c
@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 256
+
+int main(){
+    // Define variables and ask for parameters
+    int i=0, j=0;
+    char sentence[N], fixedSentence[N];
+    printf("Type a sentence\n");
+    // fgets instead of gets for buffer protection
+    fgets(sentence, N, stdin);
+    // Fix the sentence's multiple spaces
+    while(sentence[i]!='\0'){
+        if(sentence[i] == ' ' && sentence[i+1] == ' '){
+            i++;
+            continue;
+        } else {
+            fixedSentence[j]=sentence[i];
+            i++;
+            j++;
+        }
+    }
+    // Print the result after apprending the end of string to the fixed variable
+    fixedSentence[j+1] = '\0';
+    printf("\nThe sentence with fixed spaces is:\n%s", fixedSentence);
+    return 0;
+}
\ No newline at end of file
diff --git a/src/Boletin_4/Ejercicio_36.c b/src/Boletin_4/Ejercicio_36.c
new file mode 100644
index 0000000..74c3b32
--- /dev/null
+++ b/src/Boletin_4/Ejercicio_36.c
@@ -0,0 +1,48 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#include <stdbool.h>
+#define N 100
+
+void factorialDecomp(int toDecomp){
+    int factors[N], primes=2, loops=0, og=toDecomp;
+    // Check if its 1 or 0 and just print out that the decomp is 1
+    if(toDecomp == 0 | toDecomp == 1){
+        printf("\nNumber %d factorial decomposition is: 1", og);
+        return;
+    }
+    // Repeat the factorization with each reduced number until its 0
+    for(int i=0;i<N;i++){factors[i]=0;}
+    while(toDecomp != 1){
+        if(toDecomp%primes == 0){
+            toDecomp/=primes;
+            factors[loops]=primes;
+            loops++;
+            primes=2;
+        } else {primes++;}
+    }
+    // Print the result
+    printf("\nNumber %d factorial decomposition is: ", og);
+    for(int i=0;factors[i]!=0;i++){
+        if(factors[i+1]==0){
+            printf("%d", factors[i]);
+        } else {printf("%d*", factors[i]);}
+    }
+}
+
+int main(){
+    // Define variables and ask for parameters
+    int decompose[5];
+    printf("Type 5 integers separated by spaces:\n");
+    // Its just 5 parameters no for loop needed here
+    scanf("%d %d %d %d %d", &decompose[0], &decompose[1], &decompose[2], &decompose[3], &decompose[4]);
+    // Repeat the decomp for all numbers
+    for(int i=0;i<5;i++){
+        factorialDecomp(decompose[i]);
+    }
+    printf("\n");
+    return 0;
+}
\ No newline at end of file
diff --git a/src/Boletin_4/Ejercicio_37.c b/src/Boletin_4/Ejercicio_37.c
new file mode 100644
index 0000000..89dc693
--- /dev/null
+++ b/src/Boletin_4/Ejercicio_37.c
@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h>
+#define N 11
+#define M 100
+
+void checkLeaps(int n, int year){
+    int closeLeap, leaps[M], counter=1;
+    //Check closest
+    for(int i=0;i<4;i++){
+        if((year+i)%4 == 0){
+            closeLeap = year+i;
+            break;
+        }
+    }
+    // Get all the following leap years until the max amount is satisfied
+    leaps[0]=closeLeap;
+    while(counter != 100){
+        leaps[counter]=closeLeap+(4*counter);
+        counter++;
+    }
+    // Print results
+    printf("\nFollowing 100 leap years:\n");
+    for(int i=0; i<M; i++){
+        printf("%d ", leaps[i]);
+    }
+    printf("\n\n");
+}
+
+int main(){
+    // Define variables
+    char date[N];
+    int day, month, year;
+    // Endless loop so the user can change parameters (1==1)
+    while(1){
+        // Ask for parameters
+        printf("Input a date in the dd/mm/yyyy format: ");
+        scanf("%d/%d/%d", &day, &month, &year);
+        // Fix the string so it can be passed to the function more easily
+        snprintf(date, N, "%02d/%02d/%04d", day, month, year);
+        checkLeaps(100, year);
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/src/Boletin_4/Ejercicio_40.c b/src/Boletin_4/Ejercicio_40.c
new file mode 100644
index 0000000..f49bc08
--- /dev/null
+++ b/src/Boletin_4/Ejercicio_40.c
@@ -0,0 +1,187 @@
+// SPDX-FileCopyrightText: 2024 Sprinter05
+//
+// SPDX-License-Identifier: GPL-3.0-only
+
+// Libraries
+#include <stdio.h> // Main library
+#include <stdlib.h> // For managing the program
+#include <stdbool.h> // Bool function
+#include <unistd.h> // Use UNIX commands
+#include <time.h> // For random numbers
+#define N 16 // Change this number to change the matrix size
+#define SPEED 2 // Higher means faster: MUST BE GREATER OR EQUAL THAN 1
+#define clear() printf("\033[H\033[J") // Clean screen
+
+// NOTE: RUN FROM VSCODE TERMINAL OR THE MODERN WINDOWS TERMINAL APP NOT CMD OTHERWISE UTF-8 EMOJIS WILL NOT DISPLAY
+// ALSO MAKE SURE UTF-8 SUPPORT IS ENABLED IN YOUR TERMINAL OF CHOICE, APPLIES TO ALL OPERATING SYSTEMS
+
+int gameOfLife[N][N];
+int updatedGame[N][N];
+int ticks=0; // Generations
+
+// THIS IS THE MATRIX THAT WILL RUN IF THE OPTION c (choose) IS CHOSEN AT RUNTIME
+// THIS EXAMPLE MATRIX IS OF SIZE 16X16 SO IF YOU CHANGE N MODIFY THE SIZE HERE TOO
+// 0 = DISABLED, 1 = ENABLED
+int chooseGameOfLife[N][N] = {
+    {1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+    {1,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0},
+    {0,0,1,1,0,0,0,1,0,0,1,0,0,0,0,0},
+    {0,0,1,1,0,0,0,1,0,0,1,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0},
+    {0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0},
+    {0,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,1,0,0,0,1,1,0,0,0,0},
+    {0,0,1,0,0,1,0,0,0,0,1,0,1,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
+};
+
+// Make sure the cell is not outsided of the matrix
+bool outOfBound(int row, int column){
+    bool oob;
+    if(row >= N || row < 0 || column >= N || column < 0){oob = true;}
+    else {oob = false;}
+    return oob;
+}
+
+// Check rules 1, 2 and 3 for death status
+void checkDeath(int row, int column){
+    int liveNeighbours=0;
+    // Check neighbours
+    if(outOfBound(row+1,column) == false){if(gameOfLife[row+1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column+1) == false){if(gameOfLife[row+1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column-1) == false){if(gameOfLife[row+1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column) == false){if(gameOfLife[row-1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column+1) == false){if(gameOfLife[row-1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column-1) == false){if(gameOfLife[row-1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column+1) == false){if(gameOfLife[row][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column-1) == false){if(gameOfLife[row][column-1] == 1){liveNeighbours++;}}
+    // Any live cell with fewer than two live neighbours dies, as if by underpopulation.
+    if(liveNeighbours<2){updatedGame[row][column]=0;}
+    // Any live cell with two or three live neighbours lives on to the next generation.
+    else if(liveNeighbours>=2 && liveNeighbours<=3){updatedGame[row][column]=1;}
+    // Any live cell with more than three live neighbours dies, as if by overpopulation.
+    else if(liveNeighbours>3){updatedGame[row][column]=0;}
+}
+
+// Check rule 4 for revive status
+void checkRevive(int row, int column){
+    int liveNeighbours=0;
+    // Check neighbours
+    if(outOfBound(row+1,column) == false){if(gameOfLife[row+1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column+1) == false){if(gameOfLife[row+1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row+1,column-1) == false){if(gameOfLife[row+1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column) == false){if(gameOfLife[row-1][column] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column+1) == false){if(gameOfLife[row-1][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row-1,column-1) == false){if(gameOfLife[row-1][column-1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column+1) == false){if(gameOfLife[row][column+1] == 1){liveNeighbours++;}}
+    if(outOfBound(row,column-1) == false){if(gameOfLife[row][column-1] == 1){liveNeighbours++;}}
+    // Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
+    if(liveNeighbours==3){updatedGame[row][column]=1;}
+    // Remain dead
+    else {updatedGame[row][column]=0;}
+}
+
+// Run a generation
+void tick(){
+    // Run generation
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            if(gameOfLife[i][j] == 1){checkDeath(i, j);continue;}
+            else if(gameOfLife[i][j] == 0){checkRevive(i, j);continue;}
+            else {exit(1);} // Impossible case, exit with error
+        }
+    }
+}
+
+// Show the game matrix
+void displayMatrix(){
+    printf("\n");
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            if(updatedGame[i][j] == 0){printf("⬛");}
+            if(updatedGame[i][j] == 1){printf("⬜");}            
+        }
+        printf("\n");
+    }
+    printf("Generation %d\n", ticks);
+}
+
+// Print the initial status
+void printInitial(){
+    printf("\n");
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            if(gameOfLife[i][j] == 0){printf("⬛");}
+            if(gameOfLife[i][j] == 1){printf("⬜");}
+        }
+        printf("\n");
+    }
+    printf("Initial status\n");
+}
+
+// Swap og and updated matrix
+void redoMatrix(){
+    // Put updated matrix into the original one
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            gameOfLife[i][j]=updatedGame[i][j];
+        }
+    }
+    // Set the updated matrix to 0
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            updatedGame[i][j]=0;
+        }
+    }
+}
+
+// Initial random condition
+void randCondition(){
+    srand(time(NULL));
+    // Random init
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            gameOfLife[i][j]=rand()%2;
+        }
+    }
+}
+
+int main(){
+    // Ask what to do
+    char answ;
+    while(answ != 'r' && answ != 'c'){
+        printf("Do you want a randomly generated generation or choose one? (r/c): ");
+        scanf("%c", &answ);
+        if(answ == 'r'){randCondition();}
+        else if(answ == 'c'){
+            for(int i=0; i<N; i++){
+                for(int j=0; j<N; j++){
+                    gameOfLife[i][j] = chooseGameOfLife[i][j];
+                }
+            }
+        }
+    }
+    // Start dead cells on updated
+    for(int i=0;i<N;i++){
+        for(int j=0;j<N;j++){
+            updatedGame[i][j]=0;
+        }
+    }
+    printInitial(); // Print initial state
+    usleep(1000000);
+    while(1){
+        clear(); // Clear screen
+        tick(); // Run generation
+        displayMatrix(); // Show the matrix
+        ticks++; // Increase counter
+        redoMatrix();
+        usleep(200000/SPEED); // Wait delay
+    }
+    return 0;
+}
\ No newline at end of file