#!/usr/local/bin/python2

class A(object):
    def __init__(self):
        print 'A',

class B(A):
    def __init__(self):
        print 'B',
        super(B, self).__init__()

class C(A):
    def __init__(self):
        print 'C',
        super(C, self).__init__()

class D(B, C):
    def __init__(self):
        print 'D',
        super(D, self).__init__()