def mark_as_retweet(tweets):
    """
    Mark tweet as retweet seeking a concrete number.

    tweets -- list of strings containing sanitized tweets
    return -- list of strings maked as retweets with the '♻' symbol
    """
    coincidence = []
    for num in enumerate(tweets):
        if '59bcc3ad6775562f845953cf01624225' in num[1]:
            coincidence.append(num[0])
    for coinc in coincidence:
        if coinc + 1 < len(tweets):
            tweets[coinc + 1] = '♻' + tweets[coinc + 1]
    for coinc in reversed(coincidence):
        tweets.pop(coinc)
    return tweets
