N,K=map(int,input().split())
mod=998244353
if K<4*N:
  print(0)
  exit()
dp=[[0]*(16*N**2) for k in range(60)]
g=pow(5,-1,mod)
e=(4*g)%mod
t=(3*g)%mod
for i in range(4*N):
  if i<4*N-1:
    dp[0][i*(4*N)+i+1]=g
  if i%4==0:
    dp[0][i*(4*N)+0]=e
  else:
    dp[0][i*(4*N)+1]=g
    dp[0][i*(4*N)+0]=t
for k in range(1,60):
  for i in range(4*N):
    for j in range(4*N):
      for w in range(4*N):
        dp[k][i*4*N+j]+=dp[k-1][i*4*N+w]*dp[k-1][w*4*N+j]
        dp[k][i*4*N+j]%=mod
A=[[0]*(4*N) for i in range(4*N)]
for i in range(4*N):
  A[i][i]=1
rest=K-1
for k in range(60):
  if (rest>>k)&1:
    A2=[[0]*(4*N) for i in range(4*N)]
    for i in range(4*N):
      for j in range(4*N):
        for w in range(4*N):
          A2[i][j]+=A[i][w]*dp[k][w*4*N+j]
          A2[i][j]%=mod
    for i in range(4*N):
      for j in range(4*N):
        A[i][j]=A2[i][j]
result=0
result=A[0][4*N-1]*g
result%=mod
print(result)