#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, M, ans(1), t, x;
  scanf("%d%d", &N, &M), t = M, x = (M << 1) - 1;
  for (int i = 1; i <= N; ++i)
    ans = (1ll * ans * M) % 1000000007 + t,
    ans >= 1000000007 ? ans -= 1000000007 : 0, t = 1ll * t * x % 1000000007;
  return printf("%d\n", ans), 0;
}

### 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;
int main() {
  int N, M, ans(1), t, x;
  scanf("%d%d", &N, &M), t = M, x = (M << 1) - 1;
  for (int i = 1; i <= N; ++i)
    ans = (1ll * ans * M) % 1000000007 + t,
    ans >= 1000000007 ? ans -= 1000000007 : 0, t = 1ll * t * x % 1000000007;
  return printf("%d\n", ans), 0;
}

```