#include <bits/stdc++.h>
using namespace std;
const int N = 200005;
const int mod = 1e9 + 7;
int n, m;
int main() {
  scanf("%d%d", &n, &m);
  long long ans = 1, em = 1;
  while (n--) {
    ans = ((2 * m - 1) * ans % mod + em) % mod;
    em = em * m % mod;
  }
  cout << ans << endl;
  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 N = 200005;
const int mod = 1e9 + 7;
int n, m;
int main() {
  scanf("%d%d", &n, &m);
  long long ans = 1, em = 1;
  while (n--) {
    ans = ((2 * m - 1) * ans % mod + em) % mod;
    em = em * m % mod;
  }
  cout << ans << endl;
  return 0;
}

```