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


int main(){
    int x;  cin >> x;

    vector<int> move = { 2, 2, -1, -1, 2, -1, -1 };
    int now = 0;
    int ans = 0;
    for(int i = 0; i < 100; ++i){
        for(int d : move){
            now += d;
            ans += abs(d);
            if(now == x){
                cout << ans << endl;
                return 0;
            }
        }
    }

    return 0;
}