# This averagtes a list of positive numbers

def main():
    counter = 0  # counter is the number of nonzero values read in
    sum = 0.0
    num = 1
    while num != 0:
        num = input ("Enter the next number: " )
        if num != 0:
            sum = sum + num
            counter = counter + 1
    average = sum/counter
    print "The average is %.2f" % average

main()