# Compute the average of a collection of positive values entered by the user.
# The user will enter 0 or a negative number to indicate that no further
# values will be entered.  The 0 or negative number is *NOT* included in the
# average.

# Initialize total and count
total = 0
count = 0

# Read the first value from the user
val = float(input("Enter a number (0 or negative to quit): "))

# While the input is positive
while val > 0:
  # Add the input value to the total
  total = total + val

  # Increment count
  count = count + 1

  # Read the next input value
  val = float(input("Enter a number (0 or negative to quit): "))

if count > 0:
  # Compute the average
  average = total / count

  # Display the result
  print("The average of those values is", average)
else:
  print("An average cannot be displayed because no values were entered.")