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

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

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]>>>.