def METHOD_NAME(s):
    """check if a string is a correct byo-yomi time: at least '3x30 byo-yomi'
    We don't have settings for that... for now"""
    if s.find('byo-yomi') == -1:
        return False
    else:
        a = s.find('x')
        n = int(s[0:a])
        b = s.find(' ')
        t = int(s[a + 1:b])
    return n >= 3 and t >= 30