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

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]>>>.