#include <bits/stdc++.h>
using namespace std;
const int Maxn = 1000 * 1000 + 5, Mod = 1000 * 1000 * 1000 + 7;
long long n, m, powm[Maxn], pow2m[Maxn], ans;
int main() {
  cin >> n >> m;
  powm[0] = 1;
  for (int i = 1; i < Maxn; i++) powm[i] = (powm[i - 1] * m) % Mod;
  pow2m[0] = 1;
  for (int i = 1; i < Maxn; i++) pow2m[i] = (pow2m[i - 1] * (2 * m - 1)) % Mod;
  ans = powm[n];
  for (int i = 0; i < n; i++)
    ans += (powm[i + 1] * pow2m[n - i - 1]) % Mod, ans %= Mod;
  cout << ans << endl;
  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;
const int Maxn = 1000 * 1000 + 5, Mod = 1000 * 1000 * 1000 + 7;
long long n, m, powm[Maxn], pow2m[Maxn], ans;
int main() {
  cin >> n >> m;
  powm[0] = 1;
  for (int i = 1; i < Maxn; i++) powm[i] = (powm[i - 1] * m) % Mod;
  pow2m[0] = 1;
  for (int i = 1; i < Maxn; i++) pow2m[i] = (pow2m[i - 1] * (2 * m - 1)) % Mod;
  ans = powm[n];
  for (int i = 0; i < n; i++)
    ans += (powm[i + 1] * pow2m[n - i - 1]) % Mod, ans %= Mod;
  cout << ans << endl;
  return 0;
}

```