def count_vowels(s):
    """
    (str)-int
    return number of vowels in s.

    >>> count_vowels('The quick brown fox')
    5
    """
    lowerS = s.lower()
    vowels = ['a', 'e', 'i', 'o', 'u']
    ctr = 0
    for ch in lowerS:
        if ch in vowels:
            ctr += 1
    print ('There are {} vowels in: "{}"'.format(ctr, s))
    print ()
    return ctr