# Filename: factorial.py
# Author: Brian L. Walter
# Description of contents:
#   A simple program that computes factorials, demonstrating
#   the use of for loops.

def main():
    # Welcome the user.
    print ("\nI feel so free to compute factorials for your utter delight.")

    # Get the number to compute the factorial of.
    num = int(raw_input("\nPlease enter a nonnegative integer: "))

    # Initialize fact, which accumulates the output value.
    fact = 1
    # Multiply fact by the integers from 1 to the input value.
    for i in range(num):
        fact *= (i+1)

    # Print out the result.
    print str(num) + "! = " + str(fact) + ".  " \
          + "I feel special!"

    # Wait for the user to hit enter before exiting.
    raw_input("\nHit enter to exit.")

main()