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

ll my_pow(ll x, ll n, ll mod){
    ll ret;
    if (n == 0){
        ret = 1;
    }
    else if (n % 2 == 0){
        ret = my_pow((x * x) % mod, n / 2, mod);
    }
    else if (n % 2 == 1){
        ret = (x * my_pow((x * x) % mod, n / 2, mod)) % mod;
    }
    return ret;
}

ll inv(ll x, ll mod){
    return my_pow(x, mod - 2, mod);
}

ll comb(ll n, ll r, vector<ll> &fact, vector<ll> &fact_inv, ll mod){
    ll ret = (fact_inv[r] * fact_inv[n - r]) % mod;
    ret = (ret * fact[n]) % mod;
    return ret;
}

int main(){
    ll N;
    cin >> N;

    ll mod = 998244353;

    vector<ll> fact(N + 2, 0);
    fact[0] = 1;
    for (ll i = 0; i <= N; i++){
        fact[i + 1] = (fact[i] * (i + 1)) % mod;
    }

    vector<ll> fact_inv(N + 2);
    for (ll i = 0; i <= N + 1; i++){
        fact_inv[i] = inv(fact[i], mod);
    }

    vector<ll> pow_25(N + 2);
    pow_25[0] = 1;
    for (ll i = 0; i <= N; i++){
        pow_25[i + 1] = (pow_25[i] * 25LL) % mod;
    }

    ll ans = 0;
    
    for (ll i = 0; i <= N; i++){
        ll comb1 = comb(N, i, fact, fact_inv, mod);
        comb1 = (comb1 * pow_25[N - i]) % mod;
        ans = (ans + comb1 * (i / 3)) % mod;
    }
    cout << ans << endl;
}