#include <bits/stdc++.h>
using namespace std;
const int N = 35;
vector<long long> is_prime(N + 1, true);
bool sortinrev(const pair<int, int> &a, const pair<int, int> &b) {
  return (a.first > b.first);
}
bool sortbysecdesc(const pair<int, int> &a, const pair<int, int> &b) {
  return a.second > b.second;
}
bool sortbysec(const pair<int, int> &a, const pair<int, int> &b) {
  return (a.second < b.second);
}
long long powerm(long long a, long long k) {
  if (!k) {
    return 1;
  }
  long long b = powerm(a, k / 2);
  b = b * b % (1000000000 + 7);
  if (k % 2) {
    return a * b % (1000000000 + 7);
  } else {
    return b;
  }
}
long long int power(long long int a, long long int b) {
  if (b == 1) return a;
  if (b == 0) return 1;
  long long int m1 = power(a, b / 2);
  if (b % 2) return m1 * m1 * a;
  return m1 * m1;
}
void seive_of_eras(long long n) {
  is_prime[0] = 0;
  is_prime[1] = 0;
  for (long long i = 2; i * i <= n; i++) {
    if (is_prime[i]) {
      for (long long j = i * i; j <= n; j += i) {
        is_prime[j] = false;
      }
    }
  }
}
bool isprime(long long a) {
  if (a <= 1) return false;
  if (a == 2 || a == 3) return true;
  if (a % 2 == 0 || a % 3 == 0) return false;
  for (long long i = 5; i * i <= a; i = i + 6) {
    if (a % i == 0 || a % (i + 2) == 0) return false;
  }
  return true;
}
long long fact[N], invfact[N];
void initialize_nCr() {
  long long p = (1000000000 + 7);
  fact[0] = 1;
  for (long long i = 1; i < N; i++) {
    fact[i] = fact[i - 1] * i % p;
  }
  invfact[N - 1] = powerm(fact[N - 1], p - 2);
  for (long long i = N - 2; i >= 0; i--) {
    invfact[i] = invfact[i + 1] * (i + 1) % p;
  }
}
long long nCr(long long n, long long r) {
  if (r > n | n < 0 || r < 0) return 0;
  return fact[n] * invfact[r] % (1000000000 + 7) * invfact[n - r] %
         (1000000000 + 7);
}
void codeit() {
  long long n;
  cin >> n;
  long long ans =
      (n * (n - 1) * (n - 2) * (n - 3) * (n - 4)) / (5 * 4 * 3 * 2 * 1);
  ans = ans * n * (n - 1) * (n - 2) * (n - 3) * (n - 4);
  cout << ans << '\n';
  return;
}
int main() {
  long long tt;
  tt = 1;
  for (long long i = 0; i < tt; i++) codeit();
}
