mod = 998244353
n, m = map(int, input().split())
dp = [0] * (m + 1)
dp[0] = 1
for i in range(n):
    ndp = dp.copy()
    for j in range(m + 1):
        for k in range(j):
            ndp[j] += dp[k] * dp[j - k - 1]
            ndp[j] %= mod
    dp = ndp
print(dp[-1])