#include <bits/stdc++.h>
int main() {
  int i, j, k, l, n;
  long long int x, y;
  scanf("%d", &n);
  x = n;
  i = 1;
  while (i < 5) {
    x *= (n - i);
    i++;
  }
  y = x / 120;
  x = x * y;
  printf("%I64d\n", x);
}
