A grid of size NxM where each cell of the grid is filled with  some color. Find minimum number of clicks to make monochromatic grid (having one color). Problem reference (https://www.urionlinejudge.com.br/challenges/en/4b85c9eff62f37e3d169f4f62b67a6b655a6ccb1.html )

When the player clicks on any cell of the grid of color α, the cell in the top-leftmost corner of the grid, of color β, receives the color α, but not only it: all those cells which are connected to the source by paths which use only the colors α or β also receive the color α. 

The connection between cells should be considered only in the horizontal and vertical directions to form the paths. For example, when the player clicks on the cell highlighted in the figure to the left, the grid receives the coloring of the figure to the right.

find minimum number of clicks to make monochromatic grid

Input Description

    The first line is number of test cases.The next line of the input consists
    of 2 integers N and M (1 ≤ N ≤ 4, 1 ≤ M ≤ 5), which represent respectively
    the number of lines and the number of columns of the grid. The N lines
    following describe the initial configuration of the grid, representing 
    each color by an integer between 0 and 9.

Output Description

    Print a line containing a single integer that represents the minimum number 
    of clicks that the player must do in order to make the grid monochromatic.

Test Cases:

3
4 5
00162
30295
45033
01837
4 5
01234
12345
23456
34567
4 5
01234
34567
67890
90123

Expected output:

10
7
12

How to find minimum number of clicks to make monochromatic grid



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