#include <bits/stdc++.h>
using namespace std;
using ll=long long;

int main(){
    ll A,B;
    cin>>A>>B;
    ll mod=1e9+7;
    if(A%2==0){
        ll ans=A+1;
        ans%=mod;
        ll t=(B/2)%mod;
        t*=(A%mod);
        t%=mod;
        t*=2;
        t%=mod;
        ans=(ans+t+10*mod)%mod;
        t=((B/2)%mod);
        t*=((A+1)%mod);
        t%=mod;
        t*=2;
        ans=(ans+t+10*mod)%mod;
        if(B%2==1){
            ans+=(2*(A%mod))%mod;
            ans=(ans+10*mod)%mod;
        }
        cout<<ans<<endl;
    }else{
        ll ans=A%mod;
        ll t=(B/2)%mod;
        t*=(A%mod);
        t%=mod;
        t*=2;
        t%=mod;
        ans=(ans+t+10*mod)%mod;
        t=(B/2)%mod;
        t*=((A+1)%mod);
        t%=mod;
        t*=2;
        ans=(ans+t+10*mod)%mod;
        if(B%2==1){
            ans+=2*((A+1)%mod);
            ans=(10*mod+ans)%mod;
        }
        cout<<ans<<endl;
    }
    return 0;
}