def extract_teams(summary):
    """
    split the summary to get team names: 
    teamA - team B
    
    return team names if found, (None, None) otherwise
    """
    if summary.startswith((
        "AS SAINT-ÉTIENNE",
        "AS SAINT-?TIENNE",
        "PARIS SAINT-GERMAIN"
    )):
        a1, a2, b = summary.split('-', 2)
        return "%s-%s" % (a1, a2), b

    return summary.split('-', 1)