#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
const int N = 1e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;
int n;
long long C(int n, int m) {
  long long ret = 1;
  m = min(m, n - m);
  for (int i = 0; i < m; ++i) {
    ret *= n - i;
    ret /= i + 1;
  }
  return ret;
}
int main() {
  ios_base::sync_with_stdio(0);
  scanf("%d", &n);
  long long ans = C(n, 5) * C(n, 5) * 120;
  printf("%I64d\n", ans);
  return 0;
}
