#include <bits/stdc++.h>
using namespace std;
const long long inf = 1e18;
const long long mod = 1e9 + 7;
const long long N = 2e5 + 1;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long n, m;
  cin >> n >> m;
  ;
  long long ans = 2 * m, p = 1;
  for (long long i = (2); i <= (n); i++) {
    p = p * m % mod;
    ans = (ans * (2 * m - 1) + p) % mod;
  }
  cout << ans << '\n';
  ;
}

### Prompt

Your task is to create a Cpp solution to the following problem:

For a sequence a of n integers between 1 and m, inclusive, denote f(a) as the number of distinct subsequences of a (including the empty subsequence).

You are given two positive integers n and m. Let S be the set of all sequences of length n consisting of numbers from 1 to m. Compute the sum f(a) over all a in S modulo 109 + 7.

Input

The only line contains two integers n and m (1 ≤ n, m ≤ 106) — the number of elements in arrays and the upper bound for elements.

Output

Print the only integer c — the desired sum modulo 109 + 7.

Examples

Input

1 3


Output

6


Input

2 2


Output

14


Input

3 3


Output

174

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
const long long inf = 1e18;
const long long mod = 1e9 + 7;
const long long N = 2e5 + 1;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long n, m;
  cin >> n >> m;
  ;
  long long ans = 2 * m, p = 1;
  for (long long i = (2); i <= (n); i++) {
    p = p * m % mod;
    ans = (ans * (2 * m - 1) + p) % mod;
  }
  cout << ans << '\n';
  ;
}

```