import string
import re


def stemmer(word):
    """Return leading consonants (if any), and 'stem' of  word"""
   
    consonants = ''.join([c for c in string.ascii_lowercase if c not in 'aeiou'])
    word = word.lower()
    match = re.match(f'([{consonants}]+)?([aeiou])(.*)', word)
    if match:
        p1 = match.group(1) or ''
        p2 = match.group(2) or ''
        p3 = match.group(3) or ''
        return (p1, p2 + p3)
    else:
        return (word, '')