empty ________________________________________ ________________________________________ ________________________________________ _________________________#______________ _______________________#_#______________ _____________##______##____________##___ ____________#___#____##____________##___ _##________#_____#___##_________________ _##________#___#_##____#_#______________ ___________#_____#_______#______________ ____________#___#_______________________ _____________##_________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________