#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
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 4000000000000000001

struct combi{
	deque<mint> kaijou;
	deque<mint> kaijou_;
	
	combi(int n){
		kaijou.push_back(1);
		for(int i=1;i<=n;i++){
			kaijou.push_back(kaijou[i-1]*i);
		}
		
		mint b=kaijou[n].inv();
		
		kaijou_.push_front(b);
		for(int i=1;i<=n;i++){
			int k=n+1-i;
			kaijou_.push_front(kaijou_[0]*k);
		}
	}
	
	mint combination(int n,int r){
		if(r>n)return 0;
		mint a = kaijou[n]*kaijou_[r];
		a *= kaijou_[n-r];
		return a;
	}
	
	mint junretsu(int a,int b){
		mint x = kaijou_[a]*kaijou_[b];
		x *= kaijou[a+b];
		return x;
	}
	
	mint catalan(int n){
		return combination(2*n,n)/(n+1);
	}
	
};
int N,K;
array<array<vector<mint>,2>,2> merge(array<array<vector<mint>,2>,2> a,array<array<vector<mint>,2>,2> b){
	
	array<array<vector<mint>,2>,2> ret;
	rep(i,2){
		rep(j,2){
			ret[i][j] = vector<mint>(K+1,0);
		}
	}
	//cout<<ret[0][0].size()<<endl;
	rep(i,2){
		rep(j,2){
			rep(k,2){
				auto t = convolution(a[i][j],b[j][k]);
				rep(l,min(K+1,(int)t.size()))ret[i][k][l] += t[l];
			}
		}
	}
	return ret;
}

int main() {
	
	combi C(300000);
	
	//int N,K;
	cin>>N>>K;
	
	mint ans = 0;
	for(int i=1;i<=N-1;i++){
		mint t = C.combination(N-1,i);
		t *= mint(i).pow(K);
		ans += t;
	}
	
	
	cout<<ans.val()<<endl;
	
    return 0;
}