#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

ll mod = 998244353;

int main(){
    ll N;
    cin >> N;
    vector<vector<ll>> dp(N + 1, vector<ll>(N + 2, 0));
    dp[0][0] = 1;
    for (ll i = 0; i < N; i++){
        for (ll j = 0; j <= N; j++){
            dp[i + 1][j + 1] = (dp[i + 1][j + 1] + dp[i][j]) % mod;
            dp[i + 1][j] = (dp[i + 1][j] + dp[i][j] * 25LL) % mod;
        }
    }
    ll ans = 0;
    for (ll j = 0; j <= N; j++){
        ans = (ans + dp[N][j] * (j / 3)) % mod;
    }
    cout << ans << endl;
}