#include <bits/stdc++.h>
using namespace std;
template <long long MOD>
class ModInt {
 public:
  ModInt() : value(0) {}
  ModInt(long long val) : value(val < 0 ? MOD + val % MOD : val % MOD) {}
  ModInt& operator+=(ModInt that) {
    value = value + that.value;
    if (value >= MOD) value -= MOD;
    return *this;
  }
  ModInt& operator-=(ModInt that) {
    value -= that.value;
    if (value < 0) value += MOD;
    return *this;
  }
  ModInt& operator*=(ModInt that) {
    value = value * that.value % MOD;
    return *this;
  }
  ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
  ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
  ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
  long long toll() const { return value; }
  int toi() const { return (int)value; }

 private:
  long long value;
};
int N, M;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  while (cin >> N >> M) {
    ModInt<1000000007ll> x = 1, y = 1;
    for (int i = 0; i < (int)N; ++i) {
      y = y * (2 * M - 1) + x;
      x *= M;
    }
    cout << y.toi() << endl;
  }
}

### 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;
template <long long MOD>
class ModInt {
 public:
  ModInt() : value(0) {}
  ModInt(long long val) : value(val < 0 ? MOD + val % MOD : val % MOD) {}
  ModInt& operator+=(ModInt that) {
    value = value + that.value;
    if (value >= MOD) value -= MOD;
    return *this;
  }
  ModInt& operator-=(ModInt that) {
    value -= that.value;
    if (value < 0) value += MOD;
    return *this;
  }
  ModInt& operator*=(ModInt that) {
    value = value * that.value % MOD;
    return *this;
  }
  ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
  ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
  ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
  long long toll() const { return value; }
  int toi() const { return (int)value; }

 private:
  long long value;
};
int N, M;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  while (cin >> N >> M) {
    ModInt<1000000007ll> x = 1, y = 1;
    for (int i = 0; i < (int)N; ++i) {
      y = y * (2 * M - 1) + x;
      x *= M;
    }
    cout << y.toi() << endl;
  }
}

```