Score : 1000 points
Note the unusual memory limit.
For a rectangular grid where each square is painted white or black, we define its complexity as follows:
You are given a grid with H horizontal rows and W vertical columns where each square is painted white or black.
HW characters from A_{11} to A_{HW} represent the colors of the squares.
A_{ij} is #
if the square at the i-th row from the top and the j-th column from the left is black, and A_{ij} is .
if that square is white.
Find the complexity of the given grid.
#
or .
.Input is given from Standard Input in the following format:
H W A_{11}A_{12}...A_{1W} : A_{H1}A_{H2}...A_{HW}
Print the complexity of the given grid.
3 3 ... .## .##
2
Let us divide the grid by the boundary line between the first and second columns. The subgrid consisting of the first column has the complexity of 0, and the subgrid consisting of the second and third columns has the complexity of 1, so the whole grid has the complexity of at most 2.
6 7 .####.# #....#. #....#. #....#. .####.# #....##
4