#
# This program finds the average of the inputed numbers.
#   Uses sentinel approach
#
#

def main():
    print "This program finds the average of inputed numbers"

    sum_=0
    counter=0
    next_value=0
    while next_value != -1000:
        sum_=sum_+next_value
        counter=counter+1
        next_value=input("Please, input a number (input -1000 if you want to stop):")
        

    average=float(sum_)/(counter-1)
    print "The average of the inputed numbers is %0.2f" % average


main()