#include #include #include using namespace atcoder; using mint = modint998244353; using namespace std; #define rep(i,n) for (int i = 0; i < (n); ++i) #define Inf32 1000000001 #define Inf64 1000000000000000001 int main(){ int n,m; cin>>n>>m; vector dp(m+1,vector(2,0)); dp[0][0] = 1; dp[1][1] = 1; rep(i,n-1){ { vector ndp(m+1,vector(2,0)); rep(j,m+1){ if(j(2,0)); rep(j,m+1){ rep(k,2){ rep(l,m+1){ if(j+l>m)break; rep(ll,2){ tdp[j+l][ll|k] += dp[j][k]*ndp[l][ll]; } } } } swap(dp,tdp); } } cout<<(dp[m][0] + dp[m][1]).val()<