#include <bits/stdc++.h>
using namespace std;
void testCase() {}
long long M = 1e9 + 7;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, m;
  cin >> n >> m;
  long long ans = 1;
  long long x = 0;
  long long cnt = 1;
  for (int i = 0; i < n; i++) {
    x = m * x + ans - x;
    x %= M;
    cnt *= m;
    cnt %= M;
    ans = cnt + m * x;
    ans %= M;
  }
  cout << ans << "\n";
}

### Prompt

In cpp, your task is to solve 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;
void testCase() {}
long long M = 1e9 + 7;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, m;
  cin >> n >> m;
  long long ans = 1;
  long long x = 0;
  long long cnt = 1;
  for (int i = 0; i < n; i++) {
    x = m * x + ans - x;
    x %= M;
    cnt *= m;
    cnt %= M;
    ans = cnt + m * x;
    ans %= M;
  }
  cout << ans << "\n";
}

```