#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
int N, M;
int main() {
  ios::sync_with_stdio(0);
  cin >> N >> M;
  long long ans = 1, power = 1;
  for (int i = 0; i < N; i++) {
    ans = (2 * M * ans % MOD - (ans - power)) % MOD;
    power = (power * M) % MOD;
  }
  if (ans < 0) ans += MOD;
  cout << ans << "\n";
  return 0;
}

### Prompt

Develop a solution in Cpp to the problem described below:

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 MOD = 1000000007;
int N, M;
int main() {
  ios::sync_with_stdio(0);
  cin >> N >> M;
  long long ans = 1, power = 1;
  for (int i = 0; i < N; i++) {
    ans = (2 * M * ans % MOD - (ans - power)) % MOD;
    power = (power * M) % MOD;
  }
  if (ans < 0) ans += MOD;
  cout << ans << "\n";
  return 0;
}

```