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

int main(){
  ll n; cin >> n;
  ll ans = 0;
  if(n==1) ans = 1;
  if(n==2) ans = 2;
  if(n==3) ans = 3;
  if(n>=4) ans = 5*(n-3)+3;
  cout << ans << endl;
  return 0;
}