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

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

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]>>>.