#include <iostream>
#define ll long long
using namespace std;

int main(){
    int n;
    cin >> n;
    int days = 0;
    int problems = n;
    while (problems > 0) {
            days++;
            if (days % 7 == 0) {
                problems += 6;
            }
            problems--;
        }
    cout << days << endl;
    return 0;
}