deleted:    ex0/ex0.py
	deleted:    ex1/ex1.py
	deleted:    ex10/ex10.py
	deleted:    ex11/ex11.py
	deleted:    ex12/ex12.py
	deleted:    ex13/ex13.py
	deleted:    ex14/ex14.py
	deleted:    ex15/ex15.py
	deleted:    ex16/ex16.py
	deleted:    ex17/ex17.py
	deleted:    ex18/ex18.py
	deleted:    ex19/ex19.py