#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

constexpr int P = 1000000007;

ll powmod(ll n, ll k) {
    ll r = 1, t = n % P;
    for (; k != 0; k /= 2) {
        if (k & 1) r = r * t % P;
        t = t * t % P;
    }
    return r;
}
ll modinv(ll n) {
    return powmod(n, P - 2);
}

int main() {
    int n;
    ll k;
    cin >> n >> k;

    ll t = k % P * ((k + 1) % P) % P * modinv(2) % P;
    t = powmod(t, n);
    ll s = ((k + 1) % P * ((k + 2) % P) % P * modinv(2) + P - 1) % P;
    s = powmod(s, n);

    s -= t;
    s %= P;
    if (s < 0) s += P;

    cout << s << endl;

    return 0;
}