#include <bits/stdc++.h>
using namespace std;
const long long Mod = 1000000007;
long long fp(long long a, long long k) {
  long long res = 1;
  while (k) {
    if (k & 1) res = res * a % Mod;
    a = a * a % Mod;
    k >>= 1;
  }
  return res;
}
int main() {
  long long n, m;
  scanf("%I64d%I64d", &n, &m);
  long long res = (m == 1 ? n + 1
                          : ((m * fp(2 * m - 1, n) - fp(m, n)) % Mod + Mod) *
                                fp(m - 1, Mod - 2) % Mod);
  printf("%I64d", res);
  return 0;
}

### Prompt

Create a solution in cpp for 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 Mod = 1000000007;
long long fp(long long a, long long k) {
  long long res = 1;
  while (k) {
    if (k & 1) res = res * a % Mod;
    a = a * a % Mod;
    k >>= 1;
  }
  return res;
}
int main() {
  long long n, m;
  scanf("%I64d%I64d", &n, &m);
  long long res = (m == 1 ? n + 1
                          : ((m * fp(2 * m - 1, n) - fp(m, n)) % Mod + Mod) *
                                fp(m - 1, Mod - 2) % Mod);
  printf("%I64d", res);
  return 0;
}

```