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

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

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]>>>.