MOD = 998244353

def inverse(n, d):
    return n * pow(d, -1, MOD) % MOD

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

def matrix(a, b):
    ans = [[0]*len(b[0]) for _ in range(len(a))]
    for i in range(len(a)):
        for j in range(len(b[0])):
            for k in range(len(b)):
                ans[i][j] += a[i][k]*b[k][j]%MOD
                ans[i][j] %= MOD
    return ans

dp = [[0]*(N*4+1) for _ in range(N*4+1)]
half = inverse(1, 5)
for i in range(N*4):
    dp[i+1][i] = half
a, b = (1-half)*inverse(3, 4)%MOD, (1-half)*inverse(1, 4)%MOD
for i in range(N*4):
    if i%4 == 0:
        dp[0][i] += (1-half)%MOD
        dp[0][i] %= MOD
    else:
        dp[0][i] += a
        dp[0][i] %= MOD
        dp[1][i] += b
        dp[1][i] %= MOD

ans = [[0] for _ in range(N*4+1)]
ans[0][0] = 1
for i in range(60):
    if 1<<i & K:
        ans = matrix(dp, ans)
    dp = matrix(dp, dp)

print(ans[-1][0])