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

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

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]>>>.