#include <bits/stdc++.h>
using namespace std;
long long power_up(long long a, long long n) {
  if (n == 1) return a;
  long long ret = power_up(a, n / 2);
  ret = (ret * ret) % 1000000007;
  if (n % 2 == 1) ret = (ret * a) % 1000000007;
  return ret;
}
int main() {
  long long m, n;
  cin >> n >> m;
  if (m == 1) {
    cout << n + 1 << endl;
    return 0;
  }
  long long ans = power_up(m, n);
  long long temp = (m * power_up(m - 1, 1000000007 - 2)) % 1000000007;
  long long vemp = power_up(m + m - 1, n);
  vemp = (vemp - ans) % 1000000007;
  if (vemp < 0) vemp += 1000000007;
  temp = (temp * vemp) % 1000000007;
  ans = (ans + temp) % 1000000007;
  cout << ans << endl;
  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;
long long power_up(long long a, long long n) {
  if (n == 1) return a;
  long long ret = power_up(a, n / 2);
  ret = (ret * ret) % 1000000007;
  if (n % 2 == 1) ret = (ret * a) % 1000000007;
  return ret;
}
int main() {
  long long m, n;
  cin >> n >> m;
  if (m == 1) {
    cout << n + 1 << endl;
    return 0;
  }
  long long ans = power_up(m, n);
  long long temp = (m * power_up(m - 1, 1000000007 - 2)) % 1000000007;
  long long vemp = power_up(m + m - 1, n);
  vemp = (vemp - ans) % 1000000007;
  if (vemp < 0) vemp += 1000000007;
  temp = (temp * vemp) % 1000000007;
  ans = (ans + temp) % 1000000007;
  cout << ans << endl;
  return 0;
}

```