diff --git a/atcoder/abc383/a.rs b/atcoder/abc383/a.rs
new file mode 100644
index 00000000..c94c0086
--- /dev/null
+++ b/atcoder/abc383/a.rs
@@ -0,0 +1,37 @@
+use std::io::Read;
+
+fn get_word() -> String {
+    let stdin = std::io::stdin();
+    let mut stdin=stdin.lock();
+    let mut u8b: [u8; 1] = [0];
+    loop {
+        let mut buf: Vec<u8> = Vec::with_capacity(16);
+        loop {
+            let res = stdin.read(&mut u8b);
+            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
+                break;
+            } else {
+                buf.push(u8b[0]);
+            }
+        }
+        if buf.len() >= 1 {
+            let ret = String::from_utf8(buf).unwrap();
+            return ret;
+        }
+    }
+}
+
+fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }
+
+fn main() {
+    let n: usize = get();
+    let mut cur = 0;
+    let mut s = 0;
+    for _ in 0..n {
+        let t: i64 = get();
+        let v: i64 = get();
+        s = 0.max(s - t + cur) + v;
+        cur = t;
+    }
+    println!("{}", s);
+}
diff --git a/atcoder/abc383/b.rs b/atcoder/abc383/b.rs
new file mode 100644
index 00000000..389c7c37
--- /dev/null
+++ b/atcoder/abc383/b.rs
@@ -0,0 +1,61 @@
+use std::io::Read;
+
+fn get_word() -> String {
+    let stdin = std::io::stdin();
+    let mut stdin=stdin.lock();
+    let mut u8b: [u8; 1] = [0];
+    loop {
+        let mut buf: Vec<u8> = Vec::with_capacity(16);
+        loop {
+            let res = stdin.read(&mut u8b);
+            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
+                break;
+            } else {
+                buf.push(u8b[0]);
+            }
+        }
+        if buf.len() >= 1 {
+            let ret = String::from_utf8(buf).unwrap();
+            return ret;
+        }
+    }
+}
+
+fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }
+
+fn main() {
+    let h: usize = get();
+    let w: usize = get();
+    let d: i32 = get();
+    let mut s = vec![];
+    for _ in 0..h {
+        s.push(get_word().chars().collect::<Vec<_>>());
+    }
+    let mut ans = 0;
+    for i in 0..h {
+        for j in 0..w {
+            if s[i][j] == '#' {
+                continue;
+            }
+            for a in 0..h {
+                for b in 0..w {
+                    if s[a][b] == '#' {
+                        continue;
+                    }
+                    let mut cnt = 0;
+                    for k in 0..h {
+                        (0..w).filter(|&l| s[k][l] == '.').for_each(|l| {
+                            let d1 = (i as i32 - k as i32).abs() + (j as i32 - l as i32).abs();
+                            let d2 = (a as i32 - k as i32).abs() + (b as i32 - l as i32).abs();
+                            if d1.min(d2) <= d {
+                                cnt += 1;
+                            }
+                        });
+                    }
+                    ans = ans.max(cnt);
+                }
+            }
+        }
+    }
+    println!("{ans}");
+}
diff --git a/atcoder/abc383/c.rs b/atcoder/abc383/c.rs
new file mode 100644
index 00000000..592aa236
--- /dev/null
+++ b/atcoder/abc383/c.rs
@@ -0,0 +1,67 @@
+use std::collections::*;
+use std::io::Read;
+
+fn get_word() -> String {
+    let stdin = std::io::stdin();
+    let mut stdin=stdin.lock();
+    let mut u8b: [u8; 1] = [0];
+    loop {
+        let mut buf: Vec<u8> = Vec::with_capacity(16);
+        loop {
+            let res = stdin.read(&mut u8b);
+            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
+                break;
+            } else {
+                buf.push(u8b[0]);
+            }
+        }
+        if buf.len() >= 1 {
+            let ret = String::from_utf8(buf).unwrap();
+            return ret;
+        }
+    }
+}
+
+fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }
+
+fn main() {
+    let h: usize = get();
+    let w: usize = get();
+    let targ_d: i32 = get();
+    let mut s = vec![];
+    for _ in 0..h {
+        s.push(get_word().chars().collect::<Vec<_>>());
+    }
+    const INF: i32 = 1 << 30;
+    let mut dist = vec![vec![INF; w]; h];
+    let mut que = VecDeque::new();
+    for i in 0..h {
+        for j in 0..w {
+            if s[i][j] == 'H' {
+                que.push_back((0, i, j));
+            }
+        }
+    }
+    let mut ans = 0;
+    while let Some((d, x, y)) = que.pop_front() {
+        if dist[x][y] <= d {
+            continue;
+        }
+        dist[x][y] = d;
+        if d <= targ_d {
+            ans += 1;
+        }
+        for &(dx, dy) in &[(1, 0), (-1, 0), (0, 1), (0, -1)] {
+            let nx = x.wrapping_add(dx as usize);
+            let ny = y.wrapping_add(dy as usize);
+            if nx >= h || ny >= w {
+                continue;
+            }
+            if s[nx][ny] == '#' {
+                continue;
+            }
+            que.push_back((d + 1, nx, ny));
+        }
+    }
+    println!("{ans}");
+}
diff --git a/atcoder/abc383/d.rs b/atcoder/abc383/d.rs
new file mode 100644
index 00000000..a5e69c69
--- /dev/null
+++ b/atcoder/abc383/d.rs
@@ -0,0 +1,63 @@
+use std::io::Read;
+
+fn get_word() -> String {
+    let stdin = std::io::stdin();
+    let mut stdin=stdin.lock();
+    let mut u8b: [u8; 1] = [0];
+    loop {
+        let mut buf: Vec<u8> = Vec::with_capacity(16);
+        loop {
+            let res = stdin.read(&mut u8b);
+            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
+                break;
+            } else {
+                buf.push(u8b[0]);
+            }
+        }
+        if buf.len() >= 1 {
+            let ret = String::from_utf8(buf).unwrap();
+            return ret;
+        }
+    }
+}
+
+fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }
+
+fn main() {
+    const W: usize = 2_000_001;
+    let mut is_prime = vec![true; W];
+    is_prime[0] = false;
+    is_prime[1] = false;
+    for i in 2..W {
+        if is_prime[i] {
+            let mut j = i * 2;
+            while j < W {
+                is_prime[j] = false;
+                j += i;
+            }
+        }
+    }
+    let n: i64 = get();
+    let mut ans = 0;
+    for p in 2..W {
+        if !is_prime[p] {
+            continue;
+        }
+        let p8 = p as i64 * p as i64;
+        let p8 = p8.saturating_mul(p8);
+        let p8 = p8.saturating_mul(p8);
+        if p8 <= n {
+            ans += 1;
+        }
+        for q in p + 1..(W - 1) / p + 1 {
+            if !is_prime[q] {
+                continue;
+            }
+            let pq = p as i64 * q as i64;
+            if pq * pq <= n {
+                ans += 1;
+            }
+        }
+    }
+    println!("{ans}");
+}
diff --git a/atcoder/abc383/remain.txt b/atcoder/abc383/remain.txt
new file mode 100644
index 00000000..20708814
--- /dev/null
+++ b/atcoder/abc383/remain.txt
@@ -0,0 +1,3 @@
+e
+f
+g