C1212121231123232233131323223313231333132322133313232213232212121   >>    C121212123112323223313132322331323133313232213331323221323221212   <<    C1212121231123232233131323223313231333132322133313232213232212123   >>      C1212121231123232233131323223313231333132322133313232213232212122   >>