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

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