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

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

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]>>>.