#include <bits/stdc++.h>
using namespace std;

#ifdef _RUTHEN
#include <debug.hpp>
#else
#define show(...) true
#endif

using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
template <class T> using V = vector<T>;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int N;
    cin >> N;
    V<mint> dp(N + 1);
    dp[0] = 1;
    rep(i, N) {
        V<mint> np(N + 1);
        rep(j, N + 1) {
            if (dp[j] == 0) continue;
            if (j < N) np[j + 1] += dp[j];
            np[j] += dp[j] * 25;
        }
        swap(np, dp);
    }
    mint ans = 0;
    rep(j, N + 1) ans += dp[j] * (j / 3);
    cout << ans.val() << '\n';
    return 0;
}