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

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