new
insert 3
insert 5
insert 9
insert 2
insert 4
size 5
root
retrieve 0 2
retrieve 1 3
retrieve 2 4
retrieve 3 5
retrieve 4 9   
exit
insert 7
root
	subtree 0
		retrieve 0 2
		retrieve 1 3
		retrieve 2 4
	exit
	subtree 1
		retrieve 0 5
		retrieve 1 7
		retrieve 2 9
	exit
exit
delete
summary