MOD = 998244353
N, K = map(int, input().split())

inv6 = pow(6, MOD-2, MOD)

dp = [0] * 6
dp[0] = 1
for i in range(N):
    pp = [0] * 6
    dp, pp = pp, dp
    for j in range(6):
        for k in range(1, 7):
            m = (j + k) % 6
            dp[m] += pp[j] * inv6
            dp[m] %= MOD

ans = dp[K]
print(ans)