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

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

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]>>>.