//https://atcoder.jp/contests/oupc2023-day1/submissions/49049182

#include<iostream>
#include<cassert>
#include<atcoder/modint>
#include<atcoder/convolution>
using namespace std;
using mint=atcoder::modint998244353;
using Fps=vector<mint>;
int sz(const Fps& a) { return a.size(); }
Fps inv(const Fps& a) {
	Fps res{a[0].inv()};
	for (res.reserve(sz(a)); sz(res) < sz(a);) {
		Fps buf(2 * sz(res)), fres(sz(buf));
		std::copy(a.begin(), a.begin() + std::min(sz(buf), sz(a)), buf.begin());
		std::copy(res.begin(), res.end(), fres.begin());
		atcoder::internal::butterfly(buf);
		atcoder::internal::butterfly(fres);
		for (int i = 0; i < sz(buf); ++i) buf[i] *= fres[i];
		atcoder::internal::butterfly_inv(buf);
		std::fill(buf.begin(), buf.begin() + sz(res), 0);
		atcoder::internal::butterfly(buf);
		for (int i = 0; i < sz(buf); ++i) buf[i] *= fres[i];
		atcoder::internal::butterfly_inv(buf);
		mint coeff = -mint((1 - mint::mod()) / sz(buf)).pow(2);
		for (int i = sz(res); i < std::min(sz(buf), sz(a)); ++i) res.push_back(buf[i] * coeff);
	}
	return res;
}
int N;
long long M;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin>>N>>M;
	mint ans=0;
	{//a
		const int sz=N;
		Fps P(sz+1),Q(sz+1);
		mint fac=1;
		for(int i=0;i<=sz;i++)
		{
			fac*=mint(i+1).inv();
			P[i]=mint(M+1).pow(i+1)*fac;
			Q[i]=fac;
		}
		P=atcoder::convolution(P,inv(Q));
		fac=1;
		for(int k=1;k<=N;k++)
		{
			mint a = mint(M).pow(N-k);
			fac*=k;
			ans+=a*P[k]*fac;
		}
	}
	cout<<ans.val()<<endl;
}