#include <bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define pb push_back
using vi = vector <int>;
using ll = long long;
using pii = pair <int, int>;
//~ const ll mod = 998244353;
const ll mod = 1e9 + 7;
ll qpow(ll a, ll b, ll m = mod) { ll r = 1, t = a;
	for(; b; b /= 2) { if(b & 1) r = r * t % m; t = t * t % m; } return r; }


int main() {
	ios :: sync_with_stdio(false);
	
	int n; ll k; cin >> n >> k;
	
	ll i2 = (mod + 1) / 2;
	ll c2 = (k % mod) * ((k + 1) % mod) % mod * i2 % mod;
	
	ll ans = qpow((c2 + k) % mod, n) - qpow(c2, n);
	
	ans %= mod;
	if(ans < 0) ans += mod;
	cout << ans << '\n';
}