mod=998244353 n,m=map(int,input().split()) dp=[[0 for i in range(33)] for j in range(m+1)] dp2=[[0 for i in range(33)] for j in range(m+1)] dp[0][0]=2 dp[0][1]=2 for i in range(n-1): for j in range(0,m+1): for k in range(0,32): dp2[j+k][k+1]+=dp[j][k] dp2[j+k][k]+=dp[j][k]*2 dp2[j+k][abs(k-1)]+=dp[j][k] if j+k+1>m: break for j in range(0,m+1): for k in range(0,32): dp[j][k]=dp2[j][k]%mod dp2[j][k]=0 print(dp[m][0]%mod)