$0 = 0
$10 = 0
$11 = 0
while ($0 < H*W)
	$1 = $0/W+1
	$2 = $0%W+1
	$3 = A[$1, $2]
	$4 = B[$1, $2]
	if ($3 != $4)
		$10 = $1
		$11 = $2
	end
	$0 = $0+1
end
return ($10, $11)