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

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