n,k=map(int,input().split())
if n==1:
  print([1,1,3,3,3,1,1][k])
  exit()
M=998244353
fa=[1,1]
fb=[1,1]
for i in range(2,2*n+4+1):
  fa+=[fa[-1]*i%M]
  fb+=[fb[-1]*(M//i)*fb[M%i]*fa[M%i-1]*(-1)%M]
c=lambda n,k:fa[n]*fb[k]*fb[n-k]%M if n>=k else 0
a=0
a+=c(2*n+4,k)
if k%2==0:
  a+=c((2*n+4)//2,k//2)
if n%2:
  if k%2:
    a+=c((2*n+4-2)//2,(k-1)//2)*2
  else:
    a+=c((2*n+4-2)//2,k//2)
    a+=c((2*n+4-2)//2,(k-2)//2)
else:
  if k%2==0:
    a+=c((2*n+4)//2,k//2)
if n%2:
  if k%2==0:
    a+=c((2*n+4-2)//2,k//2)
    a+=c((2*n+4-2)//2,(k-2)//2)
else:
  if k%2==0:
    a+=c((2*n+4)//2,k//2)
a*=pow(4,M-2,M)
print(a%M)