#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
typedef long long ll;
using namespace std;

int main() {
    cin.tie(0)->sync_with_stdio(0);

    int X;
    cin >> X;

    int cur = 0, ans = 0;
    vector<int> d = {2, 2, -1, -1, 2, -1, -1};
    int idx = 0;
    while (cur != X) {
        cur += d[idx];
        ans += abs(d[idx]);
        idx = (idx + 1) % 7;
    }
    cout << ans << "\n";

    return 0;
}