#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#include <atcoder/modint>
using mint=atcoder::modint998244353;
int main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int n;
	ll k;
	cin>>n>>k;
	vector<vector<mint>> a(4*n+1,vector<mint>(4*n+1));
	mint p=((mint)5).inv();
	for(int i=0;i<4*n;i++){
		if(i%4==0){
			a[i][i+1]=p;
			a[i][0]=1-p;
		}else{
			a[i][i+1]=p;
			a[i][1]=p;
			a[i][0]=1-2*p;
		}
	}
	vector<vector<mint>> cur(4*n+1,vector<mint>(4*n+1));
	for(int i=0;i<=4*n;i++)cur[i][i]=1;
	while(k>0){
		if(k&1){
			vector<vector<mint>> nxt(4*n+1,vector<mint>(4*n+1));
			for(int i=0;i<=4*n;i++)for(int j=0;j<=4*n;j++)for(int l=0;l<=4*n;l++)nxt[i][j]+=a[i][l]*cur[l][j];
			cur=move(nxt);
		}
			vector<vector<mint>> nxt(4*n+1,vector<mint>(4*n+1));
			for(int i=0;i<=4*n;i++)for(int j=0;j<=4*n;j++)for(int l=0;l<=4*n;l++)nxt[i][j]+=a[i][l]*a[l][j];
			a=move(nxt);
			k>>=1;
	}

	cout<<cur[0][4*n].val()<<endl;
}