#include<bits/stdc++.h>
using namespace std;
int n, tong;
int main() 
{
    cin >> n;
    while (n - 5 > 0)
    {
        tong += 5 * 1800;
        n -= 6;
    }
    cout << tong + 1800 * n;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
long long n, d = 0;
int main()
{
  //freopen("NUMBER.inp" , "r", stdin);
  //froepen("NUMBER.out" , "w" , stdout);
  cin.tie(0) -> sync_with_stdio(0); cout.tie(0);
  cin >> n;
  long long ans = n;
  while (n > 5)
  {
    n -= 6;
    d += 9000;
  }
  cout << d + n * 1800;
  return 0;
}