def count_vowels(word):
    """
    This function takes a word and returns the number of vowels in that
    word.
    """
    count = 0
    for letter in word:
        if letter=="a" or letter=="e" or letter=="i" or letter=="o" or letter=="u":
            count = count + 1

    return count

def more_vowels(word1, word2):
    """
    This function takes two words and returns the one with more
    vowels. If they both have an equal number of vowels, it returns
    the first one.
    """
    if count_vowels(word1) >= count_vowels(word2):
        return word1
    else:
        return word2
    
        
### To test:
print "mouse vs. dog: " + more_vowels("mouse", "dog") + " has more vowels"
print "my vs. their: " + more_vowels("my", "their") + " has more vowels"