#include <bits/stdc++.h>
using namespace std;
int n;
long long C[105][6];
int main() {
  C[0][0] = 1;
  for (int i = 1; i <= 100; i++) {
    C[i][0] = 1;
    for (int j = 1; j <= 5; j++) C[i][j] = C[i - 1][j] + C[i - 1][j - 1];
  }
  cin >> n;
  long long ans = 1;
  for (int i = 0; i < 5; i++) ans *= (n - i);
  cout << ans * C[n][5] << "\n";
  return 0;
}
