#include <bits/stdc++.h>
using namespace std;
const int Mod = 1e9 + 7;
int n, m;
long long ans, powm[1100000], powx[1100000];
int main() {
  scanf("%d%d", &n, &m);
  powm[0] = 1;
  for (int i = 1; i <= n; i++) powm[i] = powm[i - 1] * m % Mod;
  int x = 2 * m - 1;
  powx[0] = 1;
  for (int i = 1; i <= n; i++) powx[i] = powx[i - 1] * x % Mod;
  ans = powm[n];
  for (int i = 0; i < n; i++) (ans += powm[n - i] * powx[i] % Mod) %= Mod;
  printf("%lld\n", ans);
  return 0;
}

### Prompt

Please create a solution in Cpp 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;
const int Mod = 1e9 + 7;
int n, m;
long long ans, powm[1100000], powx[1100000];
int main() {
  scanf("%d%d", &n, &m);
  powm[0] = 1;
  for (int i = 1; i <= n; i++) powm[i] = powm[i - 1] * m % Mod;
  int x = 2 * m - 1;
  powx[0] = 1;
  for (int i = 1; i <= n; i++) powx[i] = powx[i - 1] * x % Mod;
  ans = powm[n];
  for (int i = 0; i < n; i++) (ans += powm[n - i] * powx[i] % Mod) %= Mod;
  printf("%lld\n", ans);
  return 0;
}

```