Given a character matrix, your task is to identify the positions of all squares with a length of at least 3 and output the row and column numbers of the bottom-right corner of these squares. The squares are composed of the same character, and each side has a length of at least 3.

If the matrix is

E N W Y F A R
O C Z U J D Y
Z C C C C C P
N J S C C C A
M H H C C C S
P W A A P M U
R P S F M P B
H T B C X J B
O Z X A P E V

Please provide the row and column of the bottom-right vertex of the square in the character matrix with a side length of at least 3 (the answer is unique). Notice: All coordinates start from 0.  

Your answer should be in the format <<<[row, column]>>>.