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

int main()
{
  int x;
  cin >> x;
  if (x == 2)
  {
    cout << ll(1e6) << "\n";
    return 0;
  }
  double sum = 0;
  for (int i = x; i < 1e6; i++)
    sum += riemann_zeta(i) - 1;
  cout << ll(sum * 1e6) << "\n";
}