#include <bits/stdc++.h>

using namespace std;

int main() {
    int X;
    cin >> X;
    int pos = 0, cnt = 0;
    for (int i = 0; i < 100; i++) {
        pos += 2;
        cnt++;
        cnt++;
        if (pos == X) {
            cout << cnt << endl;
            break;
        }
        pos += 2;
        cnt++;
        cnt++;
        if (pos == X) {
            cout << cnt << endl;
            break;
        }
        pos--;
        cnt++;
        if (pos == X) {
            cout << cnt << endl;
            break;
        }
        pos--;
        cnt++;
        if (pos == X) {
            cout << cnt << endl;
            break;
        }
        pos += 2;
        cnt++;
        cnt++;
        if (pos == X) {
            cout << cnt << endl;
            break;
        }
        pos--;
        cnt++;
        if (pos == X) {
            cout << cnt << endl;
            break;
        }
        pos--;
        cnt++;
        if (pos == X) {
            cout << cnt << endl;
            break;
        }
    }
}