1 2 3 4 5 6 7 8 9 10
LR AAA = (AAB, XXX) AAB = (XXX, ZZZ) ZZZ = (AAB, XXX) BBA = (BBB, XXX) BBB = (BBC, BBC) BBC = (BBZ, BBZ) BBZ = (BBB, BBB) XXX = (XXX, XXX)