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)]
dp[0][0] = 1
for i in range(2*N):
    ndp = [[0 for _ in range(K+1)] for _ in range(2)]
    for j in range(K+1):
        for k in range(2):
            if dp[k][j]==0:
                continue
            if j>0:
                ndp[k][j-1] = (ndp[k][j-1] + dp[k][j]) % MOD
            if j<K:
                if j+1==K:
                    ndp[1][j+1] = (ndp[1][j+1] + dp[k][j]) % MOD
                else:
                    ndp[k][j+1] = (ndp[k][j+1] + dp[k][j]) % MOD
    dp = ndp
ans = dp[1][0]
print(ans)