#Exam 3 problem 1
def count_pos_even(num):
	sum=0
	count=0
	for i in range(num):
		n=int(input("enter integer "))
		if(n>0 and n%2==0):
			count+=1
			sum+=n
	if(count>0):
		return sum/count
	else:
		return -1
def main():
	num=int(input("enter number of inputs "))
	result=count_pos_even(num)
	if(result==-1):
		print("no positive evens")
	else:
		print("average of positive evens is", result)
main()