#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 1000000001
#define Inf64 2000000000000000001

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);
	}
	
};

//combi C(25000000);
combi C(25000000);

int main(){
	int N,K;
	cin>>N>>K;
	
	mint ans = 0;
	
	rep(i,N+1){
		
		mint v = mint(i).pow(N+K);
		v *= C.combination(N,i);
		if((N-i)%2)v *= -1;
		v /= C.kaijou[N+K];
		ans += v;
	}
	ans *= C.kaijou[K];
	ans /= mint(N).pow(K);
	cout<<ans.val()<<endl;
	return 0;
}