J_7up.cpp

#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "def.h"
#else
#define ck(...)
#endif
#define ll long long
#define pe(c) for (auto &e : c) cout << e << ' '; cout << '\n'
#define ps(b) cout << (b ? "YES" : "NO") << '\n'
const ll M = 1e9 + 7, N = 2e5 + 5;

void test(int32_t tc, int32_t tt) {
    ll n; cin >> n;
    vector<ll> ar(n); for (int i = 0; i < n; ++i) { cin >> ar[i]; }
    cout << "Case " << tc << ": ";
    for (int i = 0; i < n; ++i) {
        if (ar[i] == 7) {
            cout << i + 1;
            if (tc < tt) cout << '\n';
            return;
        }
    }
    cout << -1;
    if (tc < tt) cout << '\n';
}

int32_t main() {
    cin.tie(0)->sync_with_stdio(0); cin.exceptions(ios::failbit | ios::badbit);
    int32_t tc = 0, tt = 1;
    cin >> tt;
    while (tc < tt) test(++tc, tt);
    return 0;
}