import sys
input = sys.stdin.readline
MOD = 998244353
N, K = map(int, input().split())
dp = [[[0 for _ in range(K+1)] for _ in range(2*N+1)] for _ in range(2)]
dp[0][0][0] = 1
for i in range(2*N):
    for j in range(K+1):
        for k in range(2):
            if j>0:
                dp[k][i+1][j-1] += dp[k][i][j]
                dp[k][i+1][j-1] %= MOD
            if j<K:
                if j+1==K:
                    dp[1][i+1][j+1] += dp[k][i][j]
                    dp[1][i+1][j+1] %= MOD
                else:
                    dp[k][i+1][j+1] += dp[k][i][j]
                    dp[k][i+1][j+1] %= MOD
ans = dp[1][2*N][0]
print(ans)