#include <atcoder/all>
using namespace atcoder;
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using mint = modint998244353;
mint dp[3030][1010][3];
int main() {
    int n;cin>>n;
    dp[0][0][0]=1;
    rep(i,n)for(int j=0;j<=i/3;j++){
        rep(k,3)dp[i+1][j][k]+=23*dp[i][j][k];
        dp[i+1][j][1]+=dp[i][j][0];//c
        dp[i+1][j][1]+=dp[i][j][1];//c
        dp[i+1][j][2]+=dp[i][j][2];//c
        dp[i+1][j][0]+=dp[i][j][0];//o
        dp[i+1][j][2]+=dp[i][j][1];//o
        dp[i+1][j][2]+=dp[i][j][2];//o
        dp[i+1][j][0]+=dp[i][j][0];//n
        dp[i+1][j][1]+=dp[i][j][1];//n
        dp[i+1][j+1][0]+=dp[i][j][2];//n
    }
    mint ans = 0;
    for(int j=0;j<=n/3;j++)rep(k,3){
        ans+=dp[n][j][k]*j;
    }
    cout<<ans.val()<<endl;
    return 0;
}