import re


def tag_repeated_punctuations(tweet):
    """
    Marks repeated punctuations in tweet.
    INPUT:
        tweet: original tweet as a string
    OUTPUT:
        tweet with repeating punctuations marked
    """
    for symb in ['!', '?', '.', ',']:
        regex = '(\\' + symb + '( *)){2,}'
        tweet = re.sub(regex, symb + ' <repeat> ', tweet)
    return tweet