#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m;
  cin >> n >> m;
  long long a = 1;
  long long b = 1;
  long long c = 1000000007;
  for (int i = 0; i < n; i++) {
    b = b * (2 * m - 1);
    b = b + a;
    b = b % c;
    a = a * m;
    a = a % c;
  }
  cout << b;
  return 0;
}

### Prompt

Construct a CPP code solution to the problem outlined:

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() {
  long long n, m;
  cin >> n >> m;
  long long a = 1;
  long long b = 1;
  long long c = 1000000007;
  for (int i = 0; i < n; i++) {
    b = b * (2 * m - 1);
    b = b + a;
    b = b % c;
    a = a * m;
    a = a % c;
  }
  cout << b;
  return 0;
}

```