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

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

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]>>>.