#ACB138 C1

N=int(input())

V=list(map(int,input().split()))


def merge(mylist):
	mylist=sorted(mylist)
	curval=0
	if len(mylist)<=1:
		return mylist[0]

	curval = mylist[0]+mylist[1]
	mylist.pop(1)
	mylist.pop(0)
	mylist.append(curval/2)
	print(mylist)
	return merge(mylist)

print(merge(V))