def complete_strlist_with_capitals(src):
    """
            src := ('k', 'kl', 'klo')  -> ('k', 'kl', 'klo', 'K', 'Kl', 'Klo')
    """
    res = []
    for elem in src:
        res.append(elem)
        res.append(elem.capitalize())
    return res
