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

mod=998244353

FACT=[1]
for i in range(1,3*10**5+1):
    FACT.append(FACT[-1]*i%mod)

FACT_INV=[pow(FACT[-1],mod-2,mod)]
for i in range(3*10**5,0,-1):
    FACT_INV.append(FACT_INV[-1]*i%mod)

FACT_INV.reverse()

def Combi(a,b):
    if 0<=b<=a:
        return FACT[a]*FACT_INV[b]%mod*FACT_INV[a-b]%mod
    else:
        return 0

if N==1:
    ANS=[1,1,3,3,3,1,1]
    print(ANS[K])
    exit()

ANS=Combi(2*N+4,K)

# 回転
if K%2==0:
    ANS+=Combi(N+2,K//2)

# 横反転
if N%2==0:
    if K%2==0:
        ANS+=Combi(N+2,K//2)
else:
    # N+3のうち 1:1のものが二つ、他は1:2

    # 0個
    if K%2==0:
        ANS+=Combi(N+1,K//2)

    # 1個
    if K%2==1:
        ANS+=Combi(N+1,(K-1)//2)*2

    # 2個
    if K%2==0:
        ANS+=Combi(N+1,(K-2)//2)
 
# 縦反転
if K%2==0:
    ANS+=Combi(N+2,K//2)

print((ANS*pow(4,mod-2,mod)%mod)%mod)