660_E. Different Subsets For All Tuples
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
```python
import sys
from array import array

n, m = map(int, input().split())
dp = [array('i', [0])*(n+1) for _ in range(2)]
dp[0][0] = dp[1][0] = 1
mod = 10**9 + 7

for i in range(1, n+1):
    dp[0][i] = (dp[0][i-1] * m + dp[0][i-1] * (m-1)) % mod
    dp[1][i] = (dp[0][i-1] * m + dp[1][i-1] * m) % mod

print(dp[1][-1])

```