#Write a program that reads a sequence of positive integers between 100 
#and  999. The first integer outside of the range 100 - 999 terminates the 
#input. The program finds the average of the last digits of the even 
#numbers and the first digits of the odd numbers. You can assume that the 
#input is valid and not empty - there is at least one positive integer in 
#the input. 
def main():
	count=0
	sum=0
	num=int(input("enter int between 100 and 999 "))
	while(num>=100 and num<=999):
		if(num%2==0):
			sum=sum+num%10
		else:
			sum=sum+num//100
		count+=1
		num=int(input("enter int between 100 and 999 "))
	if(count>0):
		print(sum/count)
	else:
		print('no valid inputs')
main()