mod = 998244353
def main():
    n, m = list(map(int, input().split()))
    dp = [0] * (m+1)
    dp[0] = 1
    for i in range(n):
        for a in range(m, -1, -1):
            for b in range(a):
                dp[a] = (dp[a] + dp[b]*dp[a-1-b]) % mod
        #print(dp)
    return dp[m]

print(main())