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

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

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]>>>.