Ciel Phantomhive and his Chessboard

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Binary Search, bitmasking, Hard
Problem

Ciel Phantomhive is a good chess player.
He is having an N * M chessboard on which some squares are blocked out. In how many ways can he place one or more queens on the board, such that, no two queens attack each other? Two queens attack each other, if one can reach the other by moving horizontally, vertically, or diagonally without passing over any blocked square. At most one queen can be placed on a square. A queen cannot be placed on a blocked square.

Input:

The first line contains the number of test cases T. T test cases follow. Each test case contains integers N and M on the first line. The following N lines contain M characters each, and represent a board. A '#' represents a blocked square and a '.' represents an unblocked square.

Output:

Output T lines containing the required answer for each test case. As the answers can be really large, output them modulo 10^9+7.

Constraints:

1 ≤ T ≤ 100
1 ≤ N ≤ 50
1 ≤ M ≤ 5

Time Limit: 2
Memory Limit: 256
Source Limit:
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