import sys
input = sys.stdin.readline

N,K=map(int,input().split())

mod=998244353

DP0=[0]*(K+1)
DP1=[0]*(K+1)

DP0[0]=1

for i in range(2*N):
    #print(DP0,DP1)
    NDP0=[0]*(K+1)
    NDP1=[0]*(K+1)

    for j in range(K+1):
        if j+1<K:
            NDP0[j+1]=(NDP0[j+1]+DP0[j])%mod
        elif j+1==K:
            NDP1[K]=(NDP1[K]+DP0[j])%mod

        if j-1>=0:
            NDP0[j-1]=(NDP0[j-1]+DP0[j])%mod


        if j+1<=K:
            NDP1[j+1]=(NDP1[j+1]+DP1[j])%mod
        if j-1>=0:
            NDP1[j-1]=(NDP1[j-1]+DP1[j])%mod

    DP0=NDP0
    DP1=NDP1

print(DP1[0]%mod)