#include<bits/stdc++.h> using namespace std; #define ll long long const int mod=998244353,N=1e5+10; int n,m; int fac[N],inv[N]; int qp(int a,int b){ int x=1; while(b){ if(b&1) x=1ll*x*a%mod; a=1ll*a*a%mod;b>>=1; }return x; } int C(int u,int d){ if(u>d) return 0;if(min(u,d)<0) return 0; return 1ll*fac[d]*inv[u]%mod*inv[d-u]%mod; } int main(){ //freopen("sequence.in","r",stdin); //freopen("sequence.out","w",stdout); fac[0]=1;for(int i=1;i<=1e5+3;i++) fac[i]=1ll*fac[i-1]*i%mod; inv[(int)(1e5+3)]=qp(fac[(int)(1e5+3)],mod-2);for(int i=1e5+2;i>=0;i--) inv[i]=1ll*inv[i+1]*(i+1)%mod; int ans=0;cin>>n>>m; for(int i=0;i<=m;i++){ int dc=1ll*(m-i)*(m-i)*4%mod*C(i,n+i-1)%mod; for(int j=0;j<=n;j++){ int dt=1ll*dc*C(j,n)%mod*C(j-1,m-i-1)%mod*C(m-i,n+m-i-j-1)%mod; ans=(ans+dt)%mod; } }cout<<ans; return 0; }