what?

#include <bits/stdc++.h>
using namespace std;
unsigned long long n, ans;
int main() {
    cin >> n;
    for (unsigned long long i = 1; ; i++) {
        ans += i * 7;
        if (ans >= n)
            for (unsigned long long j = 1; j <= 7; j++) {
                ans -= i;
                if (ans < n) {
                    cout << i * 7 - j + 1 << endl;
                    return 0;
                }
            }
    }
    return 0;
}