#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;

int main() {
  ll N; cin >> N;
  if (1 <= N && N <= 3) cout << N << endl;
  else cout << 5 * (N - 3) + 3 << endl;
  return 0;
}