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E. Different Subsets For All Tuples

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputFor 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 10^{9} + 7.

Input

The only line contains two integers *n* and *m* (1 ≤ *n*, *m* ≤ 10^{6}) — the number of elements in arrays and the upper bound for elements.

Output

Print the only integer *c* — the desired sum modulo 10^{9} + 7.

Examples

Input

1 3

Output

6

Input

2 2

Output

14

Input

3 3

Output

174

Codeforces (c) Copyright 2010-2017 Mike Mirzayanov

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