#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int qpow(int x, int y) {
  int res = 1;
  while (y) {
    if (y & 1) res = 1ll * res * x % mod;
    x = 1ll * x * x % mod;
    y >>= 1;
  }
  return res;
}
int inv(int x) { return qpow(x, mod - 2); }
int n, m;
int main() {
  cin >> n >> m;
  int ans = qpow(m, n), tmp1 = qpow(m, n),
      tmp2 = 1ll * (m - 1) * inv(m) % mod + 1, tmp3 = 1;
  for (int i = 1; i <= n; i++) {
    (ans += 1ll * tmp1 * tmp3 % mod) %= mod;
    tmp3 = 1ll * tmp3 * tmp2 % mod;
  }
  cout << ans;
  return 0;
}

### Prompt

Develop a solution in cpp to the problem described below:

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 mod = 1000000007;
int qpow(int x, int y) {
  int res = 1;
  while (y) {
    if (y & 1) res = 1ll * res * x % mod;
    x = 1ll * x * x % mod;
    y >>= 1;
  }
  return res;
}
int inv(int x) { return qpow(x, mod - 2); }
int n, m;
int main() {
  cin >> n >> m;
  int ans = qpow(m, n), tmp1 = qpow(m, n),
      tmp2 = 1ll * (m - 1) * inv(m) % mod + 1, tmp3 = 1;
  for (int i = 1; i <= n; i++) {
    (ans += 1ll * tmp1 * tmp3 % mod) %= mod;
    tmp3 = 1ll * tmp3 * tmp2 % mod;
  }
  cout << ans;
  return 0;
}

```