//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using ll = long long;

ll MOD = 998244353;
ll modpow(ll x, ll a) {
  ll res = 1;
  while (a > 0) {
    if (a & 1) res = res * x % MOD;
    x = x * x % MOD;
    a = (a >> 1);
  }
  return res;
}

int main() {
  ll n; cin >> n;
  //ans = nC4 * 26^(n - 4)
  ll ans = n * (n - 1) % MOD * (n - 2) % MOD * (n - 3) % MOD;
  ans = ans * modpow(1*2*3*4, MOD - 2) % MOD;
  cout << ans * modpow(26, n - 4) % MOD << '\n';
}