Then , we have n * n grids , we get a task to let the rest of the gird to get a letter(A-Z) , and the adjacent's grid
have different letter . Also , up to down , left to right , wo must Lexicographic ascending.

There are some cases .
Each case has a number n (1 <= n <= 20).
Then n lines , we get a grids ,that wo have to finish the task .
Point:the '.' represent the grid is blank , we put a letter in it.

Print the right answer with n * n grids.