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

int main() {
    ll N;
    cin >> N;
    if (N <= 3)
        cout << N;
    else
        cout << 5LL * N - 12;
    cout << endl;

    return 0;
}