#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000005
#define Inf64 1000000000000000001LL

int main(){
	
	int N,K;
	cin>>N>>K;
	vector dp(K+1,vector<mint>(2,0));
	dp[0][0] = 1;
	rep(i,2*N){
		vector ndp(K+1,vector<mint>(2,0));
		rep(j,K+1){
			rep(k,2){
				int nj = j - 1;
				nj += k * 2;
				if(nj < 0 || nj >K)continue;
				rep(l,2){
					int nl = l;
					if(nj==K)nl = 1;
					ndp[nj][nl] += dp[j][l];
				}
			}
		}
		swap(dp,ndp);
	}
	cout<<dp[0][1].val()<<endl;
	return 0;
}