## https://yukicoder.me/problems/no/3515


MOD = 998244353

def prod_vec(matrix, vec):
    n = len(matrix)
    new_vec = [0] * n
    for i in range(n):
        for j in range(n):
            new_vec[i] += (matrix[i][j] * vec[j]) % MOD
            new_vec[i] %= MOD
    return new_vec


def prod(left, right):
    n = len(left)
    new_matrix = [[0] * n for _ in range(n)]
    for i in range(n):
        for j in range(n):
            for k in range(n):
                new_matrix[i][j] += (left[i][k] * right[k][j]) % MOD
                new_matrix[i][j] %= MOD
    return new_matrix


def main():
    N, K = map(int, input().split())

    vector = [0] * (4 * N + 1)
    vector[0] = 1

    matrix = [[0 for _ in range(4 * N + 1)] for _ in range(4 * N + 1)]
    for i in range(4 * N):
        if i % 4 == 0:
            matrix[i + 1][i] = pow(5, MOD - 2, MOD)
            matrix[0][i] = (4 * pow(5, MOD - 2, MOD)) % MOD
        else:
            matrix[i + 1][i] = pow(5, MOD - 2, MOD)
            matrix[1][i] = pow(5, MOD - 2, MOD)
            matrix[0][i] = (3 * pow(5, MOD - 2, MOD)) % MOD
    
    while K > 0:
        if K % 2 == 1:
            vector = prod_vec(matrix, vector)

        matrix = prod(matrix, matrix)
        K //= 2
    
    print(vector[-1])









if __name__ == "__main__":
    main()