//#pragma GCC optimize ("O3")
//#pragma GCC target ("avx")
#include <stdio.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <queue>
#include <cstdio>
#include <ctime>
#include <assert.h>
#include <chrono>
#include <random>
#include <numeric>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}

constexpr ll mod=1e9+7;

ll mod_pow(ll a,ll b){
	a%=mod;
	if(b==0)return 1;
	if(b==1)return a;
	ll res=mod_pow(a,b/2)%mod;
	res*=res; res%=mod;
	if(b%2)res*=a;
	return res%mod;
}


int main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	ll n,k; cin >> n >> k;
	k%=mod;
	ll res=0;
	ll pre=1;
	for(ll i=1;i<=n;i++){
		ll tmp=k*(k+3)/2%mod;
		pre=pre*tmp%mod;
	}
	res=pre;
	pre=1;
	for(ll i=1;i<=n;i++){
		ll tmp=k*(k+1)/2%mod;
		pre=pre*tmp%mod;
	}
	res-=pre;
	res%=mod;
	if(res<0)res+=mod;
	cout << res << endl;
}