#include <bits/stdc++.h>
using namespace std;
int i, j, k, n, m, p, Ans;
int main() {
  scanf("%d%d", &n, &m);
  for (i = p = Ans = 1; i <= n; i++, p = 1ll * p * m % 1000000007)
    Ans = (1ll * (2 * m - 1) * Ans % 1000000007 + p) % 1000000007;
  printf("%d\n", Ans);
  return 0;
}

### Prompt

Your challenge is to write 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;
int i, j, k, n, m, p, Ans;
int main() {
  scanf("%d%d", &n, &m);
  for (i = p = Ans = 1; i <= n; i++, p = 1ll * p * m % 1000000007)
    Ans = (1ll * (2 * m - 1) * Ans % 1000000007 + p) % 1000000007;
  printf("%d\n", Ans);
  return 0;
}

```