#include <bits/stdc++.h>
int n;
long long c(int n, int r) {
  double a = 1;
  a *= (n - 0) / 1.;
  a *= (n - 1) / 2.;
  a *= (n - 2) / 3.;
  a *= (n - 3) / 4.;
  a *= (n - 4) / 5.;
  return (long long)round(a);
}
long long p(int n, int r) {
  long long a = 1;
  a *= (n - 0);
  a *= (n - 1);
  a *= (n - 2);
  a *= (n - 3);
  a *= (n - 4);
  return a;
}
int main() {
  scanf("%d", &n);
  printf("%I64d\n", c(n, 5) * p(n, 5));
  scanf("\n");
  return 0;
}
