Mean_numbers = []
print "Please input the numbers one by one that you would like to find the mean of. When you are done type EOI"
start_numbers = ("1","2","3","4","5","6","7","8","9","0")
while True:
    numbers = str(raw_input("Number: "))
    if numbers.startswith(start_numbers[0:10]):
        x = int(numbers)
        Mean_numbers.append(x)
    elif numbers == "EOI":
        break
    else:
        print "You Can't input letters."


print "The average is ",len(Mean_numbers)/sum(Mean_numbers)