#include <bits/stdc++.h>
using namespace std;
const int long long mod = 1e9 + 7;
long long n, m;
long long zps_ak_ioi;
long long quick_pow(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b % 2 == 1) {
      ans = ans % mod * a % mod;
    }
    a = a % mod * a % mod;
    b >>= 1;
  }
  return ans;
}
int main() {
  cin >> n >> m;
  for (long long i = 1; i <= n; i++) {
    zps_ak_ioi = zps_ak_ioi % mod +
                 quick_pow(m, i) % mod * quick_pow((2 * m - 1), n - i) % mod;
  }
  cout << (zps_ak_ioi % mod + quick_pow(m, n) % mod) % mod;
  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 long long mod = 1e9 + 7;
long long n, m;
long long zps_ak_ioi;
long long quick_pow(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b % 2 == 1) {
      ans = ans % mod * a % mod;
    }
    a = a % mod * a % mod;
    b >>= 1;
  }
  return ans;
}
int main() {
  cin >> n >> m;
  for (long long i = 1; i <= n; i++) {
    zps_ak_ioi = zps_ak_ioi % mod +
                 quick_pow(m, i) % mod * quick_pow((2 * m - 1), n - i) % mod;
  }
  cout << (zps_ak_ioi % mod + quick_pow(m, n) % mod) % mod;
  return 0;
}

```