#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
int main() {
    // Input
    int X;
    cin >> X;
    
    // Simulation
    int move[7] = {2, 2, -1, -1, 2, -1, -1};
    int pos = 0;
    int ans = 0;
    rep(i, 100) {
        rep(j, 7) {
            pos += move[j];
            ans += abs(move[j]);
            if (pos == X) goto OUTPUT;
        }
    }

OUTPUT:
    // Output
    cout << ans << endl;
}