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

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

Matrix mul(Matrix A, Matrix B){
    ll L = ssize(A);
    Matrix C(L, vector<mint>(L));
    for (int i = 0; i < L; i++){
        for (int j = 0; j < L; j++){
            for (int k = 0; k < L; k++){
                C[i][j] += A[i][k]*B[k][j];
            }
        }
    }
    return C;
}

int main(){
    ll N,K; cin >> N >> K;
    Matrix A(4*N, vector<mint>(4*N));
    for (int i = 0; i < 4*N; i++){
        for (int j = 0; j < 4*N; j++){
            if (i == 0 && j % 4 == 0) {A[i][j] = 4;}
            else if (i == 0 && j % 4 != 0) {A[i][j] = 3;}
            else if (i == 1 && j % 4 != 0) {A[i][j] = 1;}
            else if (i == j + 1) {A[i][j] = 1;}
        }
    }

    Matrix A_pow(4*N, vector<mint>(4*N));
    for (int i = 0; i < 4*N; i++){A_pow[i][i] = 1;}
    ll pw = K-1;
    while (pw > 0){
        if (pw & 1){
            A_pow = mul(A_pow,A);
        }
        pw >>= 1;
        A = mul(A,A);
    }
    
    mint ans = A_pow[4*N-1][0]/mint(5).pow(K);
    cout << ans.val() << '\n';
}