#include <bits/stdc++.h>
using namespace std;
const long long M = 1e9 + 7ll;
long long n, m, ans;
long long ksm(long long x, long long w) {
  long long s = 1;
  while (w) {
    if (w & 1) s = s * x % M;
    x = x * x % M;
    w >>= 1;
  }
  return s;
}
signed main() {
  cin >> n >> m;
  ans = ksm(m, n);
  for (long long j = 0; j < n; j++)
    ans = (ans + ksm(m, n - j) * ksm(2 * m - 1, j)) % M;
  cout << ans << endl;
  return 0;
}

### Prompt

Your task is to create a Cpp solution 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 long long M = 1e9 + 7ll;
long long n, m, ans;
long long ksm(long long x, long long w) {
  long long s = 1;
  while (w) {
    if (w & 1) s = s * x % M;
    x = x * x % M;
    w >>= 1;
  }
  return s;
}
signed main() {
  cin >> n >> m;
  ans = ksm(m, n);
  for (long long j = 0; j < n; j++)
    ans = (ans + ksm(m, n - j) * ksm(2 * m - 1, j)) % M;
  cout << ans << endl;
  return 0;
}

```