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

typedef modint998244353 mint;
typedef long long ll;

//defmodfact
const int COMinitMAX = 500000;
mint fact[COMinitMAX+1], factinv[COMinitMAX+1];

void modfact(){
	fact[0] = 1;
	for (int i=1; i<=COMinitMAX; i++){
		fact[i] = fact[i-1] * i;
	}
	factinv[COMinitMAX] = fact[COMinitMAX].inv();
	for (int i=COMinitMAX-1; i>=0; i--){
		factinv[i] = factinv[i+1] * (i+1);
	}
}

mint cmb(int a, int b){
	if (a<b || b<0) return mint(0);
	return fact[a]*factinv[b]*factinv[a-b];
}
//--------


int main(){
	modfact();
	int h, w; cin >> h >> w;
	vector<mint> arr1(h+1);
	vector<mint> arr2(w+1);
	for (int i=0; i<=h/2; i++){
		arr1[h-i] = factinv[i] * factinv[h-2*i];
	}
	for (int i=0; i<=w/2; i++){
		arr2[w-i] = factinv[i] * factinv[w-2*i];
	}
	vector<mint> arr = convolution<mint>(arr1, arr2);
	mint ans = 0;
	for (int i=0; i<(int)arr.size(); i++){
		ans += fact[i] * arr[i];
	}
	cout << ans.val() << endl;
	
}