$_____________________$__________________________$
$____________________$$$_________________________$
$__$_________________$$$________________$________$
$___$$______________$$$$$_____________$$_________$
$____$$$____________$$$$$___________$$$__________$
$_____$$$$$_________$$$$$________$$$$$___________$
$______$$$$$$$______$$$$$_____$$$$$$$____________$
$________$$$$$$$____$$$$$___$$$$$$$______________$
$___________$$$$$____$$$___$$$$$_________________$
$__$$$$$$$______$$$__$$$__$$$______$$$$$$$_______$
$______$$$$$$$$____$$_$_$$____$$$$$$$$___________$
$__________$$$$$$$$$_$$$_$$$$$$$$$_______________$
$_________________$$$_$_$$$______________________$
$_____________$$$$$___$___$$$$$__________________$
$_____________________$__________________________$
-> (deep)