#include <bits/stdc++.h>
using namespace std;

int main() {
    int n; cin >> n;
    int cur = 1;
    int ans = 0;
    while (n) {
        if (cur % 7 == 0) {
            n += 6;
        }
        n--;
        ans++;
        cur++;
    }
    cout << ans << "\n";
}