#include<bits/stdc++.h>
using namespace std;
#define int long long
#define N 1000005
int n,m,ans;
const int mod=998244353;
int jc[N],njc[N];
int ksm(int x,int y){
	int ans=1;
	while(y){
		if(y&1) ans=ans*x%mod;
		x=x*x%mod,y>>=1;
	}
	return ans;
}
int C(int x,int y){
	if(x<y||x<0||y<0) return 0;
	return jc[x]*njc[y]%mod*njc[x-y]%mod;
}
int W(int x,int y){
	return C(x+y-2,y-1);
}
int F(int x,int y){
	return (W(x+1,y+1)*W(x+1,y+1)%mod-W(x,y+2)*W(x+2,y)%mod+mod)%mod;
}
signed main(){
	scanf("%lld%lld",&n,&m);
	jc[0]=njc[0]=1;
	for(int i=1;i<=max(n,m)*2;i++) jc[i]=jc[i-1]*i%mod,njc[i]=ksm(jc[i],mod-2);
	for(int i=0,o=1;i<=min(n,m);i++,o*=-1){
		ans+=o*C(n,i)*F(n,m-i)%mod,ans%=mod,ans=(ans+mod)%mod;
		//printf("%lld %lld\n",C(n,i),F(n,m-i)%mod);
	}
	printf("%lld\n",ans);
	return 0;
}