C11111211113313112113313331333133312111113331333133313311232313232212121   >>    C1111121111331311211331333133313331211111333133313331331123231323221212   <<    C11111211113313112113313331333133312111113331333133313311232313232212123   >>      C11111211113313112113313331333133312111113331333133313311232313232212122   >>