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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def how_long(length=4, choices=len(words), speed=1000 * 1000 * 1000 * 1000, optimism=2):
 """ How long might it take to guess a password? @param length: the number of words that we're going to choose. @type length: L{int} @param choice: the number of words we might choose between. @type choice: L{int} @param speed: the speed of our hypothetical password guesser, in guesses per second. @type speed: L{int} @param optimism: When we start guessing all the options, we probably won't have to guess I{all} of them to get a hit. This assumes that the guesser will have to guess only C{1/optimism} of the total number of possible options before it finds a hit. """

    return ((choices ** length) / (speed * optimism))