#3336. Uva10572 Black and White

The first line in the input contains an integer T (less than 100), the number of cases to follow. Each case starts with two integers, M and N (2 ≤ M, N ≤ 8), the number of rows and columns respectively in the grid. The next M lines contains N characters each and describes the grid using the following characters:

# - a cell which is colored black
o - a cell which is colored white
. - a cell which color has not yet been assigned

每组测试数据，输出一个数，表示方案总数