class sky(object):

    def __init__(self):

        self.plus = [ (6,1), (1,6), (11,6), (6,11) ]
        self.minus = [ (3,3), (9,3), (6,6), (3,9), (9,9) ]
class sky(object):

    def __init__(self):

        self.plus = [ (6,1), (1,6), (11,6), (6,11) ]
        self.minus = [ (3,3), (9,3), (6,6), (3,9), (9,9) ]