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

MOD = 998244353

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

P = [0]
p = inverse(1, N)
for _ in range(N):
    P.append((P[-1]+p)%MOD)

dp = [[0]*(N+1) for _ in range(K+1)]
dp[0][0] = 1
for i in range(K):
    for j in range(N+1):
        if dp[i][j] == 0:
            continue
        if j < N:
            dp[i+1][j+1] += dp[i][j]*P[N-j]
            dp[i+1][j+1] %= MOD
        if 1 <= j:
            dp[i+1][j-1] += dp[i][j]*P[j]
            dp[i+1][j-1] %= MOD

ans = 0
for i in range(N+1):
    if (K-i)%2 == 1:
        continue
    red = (K-i)//2
    ans += (N+red)*dp[-1][i]%MOD
    ans %= MOD

print(ans)