#include <bits/stdc++.h>
using namespace std;
int pw(int a, int e) {
  if (e == 0) return 1;
  int tmp = pw(a, e / 2);
  tmp = (tmp * ((long long)tmp)) % 1000000007;
  if (e % 2) tmp = (tmp * ((long long)a)) % 1000000007;
  return tmp;
}
int main() {
  int n, m;
  cin >> n >> m;
  if (m == 1) {
    cout << n + 1 << '\n';
    return 0;
  }
  int pmn = pw(m, n);
  int p2mn = pw(2 * m - 1, n);
  int ans = (p2mn + 1000000007 - pmn) % 1000000007;
  ans = (ans * ((long long)m)) % 1000000007;
  ans = (ans * ((long long)pw(m - 1, 1000000007 - 2))) % 1000000007;
  ans = (ans + pmn) % 1000000007;
  cout << ans << '\n';
  return 0;
}

### Prompt

Please provide a Cpp coded solution 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;
int pw(int a, int e) {
  if (e == 0) return 1;
  int tmp = pw(a, e / 2);
  tmp = (tmp * ((long long)tmp)) % 1000000007;
  if (e % 2) tmp = (tmp * ((long long)a)) % 1000000007;
  return tmp;
}
int main() {
  int n, m;
  cin >> n >> m;
  if (m == 1) {
    cout << n + 1 << '\n';
    return 0;
  }
  int pmn = pw(m, n);
  int p2mn = pw(2 * m - 1, n);
  int ans = (p2mn + 1000000007 - pmn) % 1000000007;
  ans = (ans * ((long long)m)) % 1000000007;
  ans = (ans * ((long long)pw(m - 1, 1000000007 - 2))) % 1000000007;
  ans = (ans + pmn) % 1000000007;
  cout << ans << '\n';
  return 0;
}

```