#include <iostream>
#include <vector>

using namespace std;
typedef long long ll;
const int MAX = 1000010;
constexpr ll mod = 1000000007;
vector<ll> gcd_trans(vector<ll> &v){
	int i,j,n = v.size();
	vector<bool> used(n,true);
	for(i=2;i<n;i++){
		if(!used[i]) continue;
		for(j=(n - 1)/i;j>=1;j--){
			used[j*i] = false;
			(v[j] += v[j*i]) %= mod;
		}
	}
	return v;
}

vector<ll> inv_gcd_trans(vector<ll> &v){
	int i,j,n = v.size();
	vector<bool> used(n,true);
	for(i=2;i<n;i++){
		if(!used[i]) continue;
		for(j=1;j*i<n;j++){
			used[j*i] = false;
			(v[j] += mod - v[j*i]) %= mod;
		}
	}
	return v;
}
vector<ll> a(3*MAX),b(3*MAX);
int main(){
	ll i,h,w;
	cin >> h >> w;
	for(i=1;i<h;i++){
		a[i] = h - i;
	}
	for(i=1;i<w;i++){
		b[i] = w - i;
	}
	a = gcd_trans(a),b = gcd_trans(b);
	for(i=0;i<a.size();i++){
		(a[i] *= b[i]) %= mod;
	}
	b = inv_gcd_trans(a);
	ll ans = (2*b[1]%mod + h*(w - 1)%mod + w*(h - 1)%mod)%mod;
	cout << ans << endl;
}