#include<bits/stdc++.h>
#define rep(i,l,r) for(int i=l;i<=r;++i)
using namespace std;
using ll =long long;
const int N=1e6+50;
const int mod=998244353;
#define int long long
#define pb push_back
ll a[N],b[N];
ll getmi(ll a,ll x)
{
    ll rt=1;
    while(x)
    {
        if(x&1) rt=rt*a%mod;
        a=a*a%mod,x>>=1;
    }
    return rt;
}
ll invv(ll x)
{
    return getmi(x,mod-2);
}
ll C(ll n,ll m)
{
    ll res=1;
    rep(i,0,m-1) res*=(n-i)*invv(i+1)%mod,res%=mod;
    return res;
}
void solve()
{
    ll n,m,T=0,r,sum=0,ans=0,ss=0;
    cin>>n>>m;
    ans+=C(n,4)%mod*C(m,2)%mod*C(m,2)%mod;
    ans%=mod;
    swap(n,m);
    ans+=C(n,4)*C(m,2)%mod*C(m,2)%mod;
    ans%=mod;
    ans-=C(n,4)*C(m,4)%mod;
    ans+=mod;
    ans%=mod;
    cout<<ans<<"\n";

}
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    int t=1;
    //cin>>t;
    while(t--)solve();
    return 0;
}