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

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

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]>>>.