N,K=map(int, input().split())
dp1 = [[0]*(K+1) for _ in range(2*N+1)]
dp1[0][0] = 1
for i in range(1, 2*N+1):
    for j in range(K+1):
        if j!=0:
            dp1[i][j] += dp1[i-1][j-1]
            dp1[i][j] %= 998244353
        if j != K:
            dp1[i][j] += dp1[i-1][j+1]
            dp1[i][j] %= 998244353
tmp = dp1[-1][0]
dp1 = [[0]*(K) for _ in range(2*N+1)]
dp1[0][0] = 1
for i in range(1, 2*N+1):
    for j in range(K):
        if j!=0:
            dp1[i][j] += dp1[i-1][j-1]
            dp1[i][j] %= 998244353
        if j != K-1:
            dp1[i][j] += dp1[i-1][j+1]
            dp1[i][j] %= 998244353
print((tmp - dp1[-1][0])% 998244353)