#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001



int main(){
	
	int n;
	cin>>n;
	
	vector<mint> dp(n+1,0);
	dp[0] = 1;
	rep(i,n){
		vector<mint> ndp(n+1,0);
		rep(j,n+1){
			ndp[j] += dp[j] * 25;
			if(j!=n)ndp[j+1] += dp[j];
		}
		swap(dp,ndp);
	}
	
	mint ans = 0;
	rep(i,n+1){
		ans += dp[i] * (i/3);
	}
	
	cout<<ans.val()<<endl;

	return 0;
}