#include <bits/stdc++.h>
using namespace std;
void fre() {
  freopen("c://test//input.in", "r", stdin);
  freopen("c://test//output.out", "w", stdout);
}
template <class T1, class T2>
inline void gmax(T1 &a, T2 b) {
  if (b > a) a = b;
}
template <class T1, class T2>
inline void gmin(T1 &a, T2 b) {
  if (b < a) a = b;
}
const int N = 0, M = 0, Z = 1e9 + 7, ms63 = 0x3f3f3f3f;
int n, m;
int main() {
  while (~scanf("%d%d", &n, &m)) {
    long long bas = 2 * m;
    long long k = 2 * m - 1;
    long long w = m;
    for (int i = 1; i < n; ++i) {
      bas = (bas * k + w) % Z;
      w = w * m % Z;
    }
    printf("%lld\n", bas);
  }
  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;
void fre() {
  freopen("c://test//input.in", "r", stdin);
  freopen("c://test//output.out", "w", stdout);
}
template <class T1, class T2>
inline void gmax(T1 &a, T2 b) {
  if (b > a) a = b;
}
template <class T1, class T2>
inline void gmin(T1 &a, T2 b) {
  if (b < a) a = b;
}
const int N = 0, M = 0, Z = 1e9 + 7, ms63 = 0x3f3f3f3f;
int n, m;
int main() {
  while (~scanf("%d%d", &n, &m)) {
    long long bas = 2 * m;
    long long k = 2 * m - 1;
    long long w = m;
    for (int i = 1; i < n; ++i) {
      bas = (bas * k + w) % Z;
      w = w * m % Z;
    }
    printf("%lld\n", bas);
  }
  return 0;
}

```