import os
clear = lambda: os.system('cls')

while 1:
    usr_input = str(raw_input("To calculate the faculty of a given number\nenter a positive interger.\nEnter <0> to quit.\n> "))

    if (usr_input == "0"):
        print "Good Bye!"
        exit(1)
    elif (usr_input != None):
        result = 1
        for i in range(1, int(usr_input)):
            result = result * i
        print "Summary of the last calculation:\n\tGiven input: %d\n\tFaculty of input: %d\n" % (int(usr_input), result)
    else:
        print "You fucked up"