#include <bits/stdc++.h>
#define DEBUG(s, a) cout << s << " : " << a << '\n'
using namespace std;

void _main() {
    int n;
    cin >> n;
    
    int sum = 0;
    while (sum < n) {
        sum++;
        if (sum%7 == 0) n += 6;
    }

    cout << sum << '\n';
    return;
}


int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    // cout << fixed << setprecision(15);
    _main();
}