#include <bits/stdc++.h>
//#define int long long
#define ll long long
#define db double
#define fi first
#define se second
#define pii pair<int,int>
#define vi vector<int>

using namespace std;

const int maxn=2e5; 
const int mod=998244353; 
int n,m;
int fac[maxn+5],ivf[maxn+5];
int add(int x,int y) {
	return (x+=y)>=mod?x-mod:x; 
}
int fpw(int x,int k,int p) {
	int ret=1;
	while (k) {
		if (k&1) ret=1ll*ret*x%p;
		x=1ll*x*x%p; k>>=1; 
	}
	return ret;
}
int C(int n,int m) {
	return 1ll*fac[n]*ivf[n-m]%mod*ivf[m]%mod;
}
int main() {
	scanf("%d %d",&n,&m);
	if (min(n,m)==1) {
		printf("%d\n",1);
		return 0; 
	}
	fac[0]=1; 
	for (int i=1;i<=maxn;i++) fac[i]=1ll*fac[i-1]*i%mod; 
	ivf[maxn]=fpw(fac[maxn],mod-2,mod);
	for (int i=maxn-1;i>=0;i--) ivf[i]=1ll*ivf[i+1]*(i+1)%mod;
	int ans=1ll*C(n+m-2,n-1)*C(n+m-2,n-1)%mod;
	ans=add(ans,mod-1ll*C(n+m-2,n-2)*C(n+m-2,m-2)%mod); 
	printf("%d\n",ans); 
	return 0;
}