# average3.py
# A program to average a set of numbers
# Illustrates sentinel loop using negative input as sentinel
def main():
sum = 0.0
count = 0
x = input("Enter a number (negative to quit) >> ")
while x >= 0:
sum = sum + x
count = count + 1
x = input("Enter a number (negative to quit) >> ")
print "\nThe average of the numbers is", sum / count
main()