#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using mint = atcoder::modint998244353;

int main(){
	int n,k;
	cin>>n>>k;
	vector<mint> dp(n+1,0);
	dp.at(0)=1;
	rep(i,k){
		vector<mint> ndp(n+1,0);
		rep(j,n+1){
			if(dp.at(j)==0) continue;
			if(j<n) ndp.at(j+1)+=(dp.at(j))*(n-j)/n;
			if(j>0) ndp.at(j-1)+=(dp.at(j))*(j)/n;
		}
		swap(dp,ndp);
	}
	mint ans=0;
	rep(i,n+1) ans+=dp.at(i)*(n+(k-i)/2);
	cout<<ans.val()<<endl;
}