#include <bits/stdc++.h>
using namespace std;
const int MN = 100005, inf = 1000000005, mod = 1000000007;
const long long INF = 1000000000000000005LL;
int main() {
  int n, m;
  scanf("%d%d", &n, &m);
  long long res = 1LL, pot = 1LL, mno = 2 * m - 1;
  for (int i = 1; i <= n; ++i) {
    res *= mno;
    res += pot;
    res %= mod;
    pot = (pot * m) % mod;
  }
  printf("%lld", res);
}

### Prompt

Please formulate 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 int MN = 100005, inf = 1000000005, mod = 1000000007;
const long long INF = 1000000000000000005LL;
int main() {
  int n, m;
  scanf("%d%d", &n, &m);
  long long res = 1LL, pot = 1LL, mno = 2 * m - 1;
  for (int i = 1; i <= n; ++i) {
    res *= mno;
    res += pot;
    res %= mod;
    pot = (pot * m) % mod;
  }
  printf("%lld", res);
}

```