def loadWords(filename):
    """
    Returns a list of valid words. Words are strings of lowercase letters.

    Depending on the size of the word list, this function may
    take a while to finish.
    """
    print("Loading word list from file...")
    inFile = open(filename, 'r')
    line = inFile.readline()
    wordlist = line.split()
    print("  ", len(wordlist), "words loaded.")
    return wordlist