#include <bits/stdc++.h>
using namespace std;

using ll=long long;
#define int ll

#define rng(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,b) rng(i,0,b)
#define gnr(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define per(i,b) gnr(i,0,b)
#define pb push_back
#define eb emplace_back
#define a first
#define b second
#define bg begin()
#define ed end()
#define all(x) x.bg,x.ed
#ifdef LOCAL
#define dmp(x) cerr<<__LINE__<<" "<<#x<<" "<<x<<endl
#else
#define dmp(x) void(0)
#endif

template<class t,class u> void chmax(t&a,u b){if(a<b)a=b;}
template<class t,class u> void chmin(t&a,u b){if(b<a)a=b;}

template<class t> using vc=vector<t>;
template<class t> using vvc=vc<vc<t>>;

using pi=pair<int,int>;
using vi=vc<int>;

template<class t,class u>
ostream& operator<<(ostream& os,const pair<t,u>& p){
	return os<<"{"<<p.a<<","<<p.b<<"}";
}

template<class t> ostream& operator<<(ostream& os,const vc<t>& v){
	os<<"{";
	for(auto e:v)os<<e<<",";
	return os<<"}";
}

using uint=unsigned;
using ull=unsigned long long;

const uint mod=998244353;
//const uint mod=1000000007;
//uint mod=1;
template<uint32_t mod>
struct ModInt{
	uint a;
	ModInt& s(uint vv){
		a=vv<mod?vv:vv-mod;
		return *this;
	}

    ModInt(ll x=0){s(x%mod+mod);}

	ModInt& operator+=(const ModInt &x){
		return s(a+x.a);
	}
	ModInt& operator-=(const ModInt &x){
		return s(a+mod-x.a);
	}
	ModInt& operator*=(const ModInt &x){
		a=ull(a)*x.a%mod;
		return *this;
	}
	ModInt& operator/=(const ModInt &x){
		*this*=x.inv();
		return *this;
	}

	ModInt operator+(const ModInt &x)const{return ModInt(*this)+=x;}
	ModInt operator-(const ModInt &x)const{return ModInt(*this)-=x;}
	ModInt operator*(const ModInt &x)const{return ModInt(*this)*=x;}
	ModInt operator/(const ModInt &x)const{return ModInt(*this)/=x;}
	bool operator==(const ModInt &x)const{return a==x.a;}
	bool operator!=(const ModInt &x)const{return a!=x.a;}

	ModInt operator-()const{return ModInt()-*this;}
	ModInt pow(int n)const{
		ModInt res(1),x(*this);
		while(n){
			if(n&1)res*=x;
			x*=x;
			n>>=1;
		}
		return res;
	}

    ModInt inv()const{return pow(mod-2);}
};


using mint=ModInt<998244353>;



template<class Mint,int32_t N>
struct ModIntTable{
	vector<Mint>facts,finvs,invs;
	ModIntTable():facts(N),finvs(N),invs(N){
		const uint32_t mod=Mint(-1).a+1;
		invs[1]=1;
		for(int i=2;i<N;i++)invs[i]=invs[mod%i]*(mod-mod/i);

		facts[0]=1;
		finvs[0]=1;
		for(int i=1;i<N;i++){
			facts[i]=facts[i-1]*i;
			finvs[i]=finvs[i-1]*invs[i];
		}
	}
	inline Mint fact(int n)const{return facts[n];}
	inline Mint finv(int n)const{return finvs[n];}
	inline Mint inv(int n)const{return invs[n];}
	inline Mint binom(int n,int k)const{return facts[n]*finvs[k]*finvs[n-k];}
};
ModIntTable<mint,1<<19>mtable;



const mint prim_root=3;


static const int LG=21;
mint roots[1<<(LG+1)],iroots[1<<(LG+1)];
struct PrepareRoots{
	PrepareRoots(){
		rep(w,LG+1){
			const int s=(1<<w)-1;
			const mint g=prim_root.pow((mod-1)/(1<<w)),ig=g.inv();
			mint p=1,ip=1;
			rep(i,1<<w){
				roots[s+i]=p;p*=g;
				iroots[s+i]=ip;ip*=ig;
			}
		}
	}
} PrepareRootsDummy;

void broken_fmt(vector<mint>&f){
	const int n=f.size();
	for(int b=n/2;b>=1;b/=2){
		for(int i=0;i<n;i+=b*2){
			rep(j,b){
				mint tmp=f[i+j]-f[i+j+b];
				f[i+j]+=f[i+j+b];
				f[i+j+b]=tmp*roots[b*2-1+j];
			}
		}
	}
}

void broken_ifmt(vector<mint>&f){
	const int n=f.size();
	for(int b=1;b<=n/2;b*=2){
		for(int i=0;i<n;i+=b*2){
			rep(j,b){
				f[i+j+b]*=iroots[b*2-1+j];
				mint tmp=f[i+j]-f[i+j+b];
				f[i+j]+=f[i+j+b];
				f[i+j+b]=tmp;
			}
		}
	}
	mint in=mint(n).inv();
	rep(i,n)
		f[i]*=in;
}

void inplace_fmt(vector<mint>&f,const bool i){
	if(!i)broken_fmt(f);
	else broken_ifmt(f);
}



vector<mint> multiply(vector<mint> x,vector<mint> y,bool same=false){
	int n=x.size()+y.size()-1;
	int s=1;
	while(s<n)s*=2;
	x.resize(s);inplace_fmt(x,false);
	if(!same){
		y.resize(s);inplace_fmt(y,false);
	}else
		y=x;
	rep(i,s)
		x[i]*=y[i];
	inplace_fmt(x,true);x.resize(n);
	return x;
}

template<class D>
struct Poly:public vc<D>{
	template<class...Args>
	Poly(Args...args):vc<D>(args...){}
	Poly(initializer_list<D>init):vc<D>(all(init)){}
	int size()const{
		return vc<D>::size();
	}
	void ups(int s){
		if(size()<s)this->resize(s,0);
	}
	Poly low(int s)const{
		return Poly(this->bg,this->bg+min(max(s,int(1)),size()));
	}
	Poly rev()const{
		auto r=*this;
		reverse(all(r));
		return r;
	}
	Poly& operator+=(const Poly&r){
		ups(r.size());
		rep(i,r.size())
			(*this)[i]+=r[i];
		return *this;
	}
	Poly& operator-=(const Poly&r){
		ups(r.size());
		rep(i,r.size())
			(*this)[i]-=r[i];
		return *this;
	}
	template<class T>
	Poly& operator*=(T t){
		for(auto&v:*this)
			v*=t;
		return *this;
	}
	Poly& operator*=(const Poly&r){
		return *this=multiply(*this,r);
	}
	Poly square()const{
		return multiply(*this,*this,true);
	}

	Poly inv(int s)const{
		Poly r{D(1)/(*this)[0]};
		for(int n=1;n<s;n*=2)
			r=r*2-(r.square()*low(2*n)).low(2*n);
		return r.low(s);
	}
	
	template<class T>
	Poly& operator/=(T t){
		return *this*=D(1)/D(t);
	}
	Poly quotient(const Poly&r,const Poly&rri)const{
		int m=r.size();
		assert(r[m-1].v);
		int n=size();
		int s=n-m+1;
		if(s<=0) return {0};
		return (rev().low(s)*rri.low(s)).low(s).rev();
	}
	Poly& operator/=(const Poly&r){
		return *this=quotient(r,r.rev().inv(max(size()-r.size(),int(0))+1));
	}
	Poly& operator%=(const Poly&r){
		*this-=*this/r*r;
		return *this=low(r.size()-1);
	}
	Poly operator+(const Poly&r)const{return Poly(*this)+=r;}
	Poly operator-(const Poly&r)const{return Poly(*this)-=r;}
	template<class T>
	Poly operator*(T t)const{return Poly(*this)*=t;}
	Poly operator*(const Poly&r)const{return Poly(*this)*=r;}
	template<class T>
	Poly operator/(T t)const{return Poly(*this)/=t;}
	Poly operator/(const Poly&r)const{return Poly(*this)/=r;}
	Poly operator%(const Poly&r)const{return Poly(*this)%=r;}
	Poly dif()const{
		Poly r(max(int(0),size()-1));
		rep(i,r.size())
			r[i]=(*this)[i+1]*(i+1);
		return r;
	}
	Poly inte()const{
		Poly r(size()+1,0);
		rep(i,size())
			r[i+1]=(*this)[i]*mtable.inv(i+1);
		return r;
	}
	//opencupXvcIII GP of Peterhof H
	Poly log(int s)const{
		return (low(s).dif()*inv(s-1)).low(s-1).inte();
	}
	//Petrozavodsk 2019w Day1 G
	//yosupo judge
	Poly exp(int s)const{
		return exp2(s).a;
	}
	pair<Poly,Poly> exp2(int s)const{
		Poly f{1},g{1};
		for(int n=1;;n*=2){
			if(n>=s)break;
			g=g*2-(g*g*f).low(n);
			//if(n>=s)break;
			Poly q=low(n).dif();
			q=q+g*(f.dif()-f*q).low(2*n-1);
			f=f+(f*(low(2*n)-q.inte())).low(2*n);
		}
		return make_pair(f.low(s),g.low(s));
	}
};

using poly=Poly<mint>;
signed main(){
	int N,M;
	cin>>N>>M;
 
	poly p(N+1);
 
	auto in=mint(N+1).inv();
	for(int i=0;i<=N;i++){
		p[i]=mtable.finv(i)*in*(N+1-i);
	}

	p=p.log(N+1);
	rep(i,N+1)p[i]*=M;
	p=p.exp(N+1);
 
	mint ans=0;
	for(int i=0;i<=N;i++){
		ans+=p[i]*mtable.finv(N-i);
	}
	ans*=mtable.fact(N);
	ans*=mint(N+1).pow(M);
	cout<<ans.a<<endl;
	return 0;
}


Measured memory_bytes: 75508