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

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