#include <bits/stdc++.h>
using namespace std;
const int NICO = 1000000 + 10;
const int MOD = 1000000000 + 7;
int n, m;
long long dp[NICO], pow_m[NICO];
int main() {
  cin >> n >> m;
  pow_m[0] = dp[0] = 1;
  for (int i = 1; i <= n; i++) {
    pow_m[i] = pow_m[i - 1] * m % MOD;
  }
  for (int i = 0; i < n; i++) {
    dp[i + 1] = (dp[i] * (2 * m - 1) + pow_m[i]) % MOD;
  }
  cout << dp[n] << endl;
}

### Prompt

Create a solution in CPP for 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 int NICO = 1000000 + 10;
const int MOD = 1000000000 + 7;
int n, m;
long long dp[NICO], pow_m[NICO];
int main() {
  cin >> n >> m;
  pow_m[0] = dp[0] = 1;
  for (int i = 1; i <= n; i++) {
    pow_m[i] = pow_m[i - 1] * m % MOD;
  }
  for (int i = 0; i < n; i++) {
    dp[i + 1] = (dp[i] * (2 * m - 1) + pow_m[i]) % MOD;
  }
  cout << dp[n] << endl;
}

```