C21231322221311331311211312111133132313223313331333112113313232233132322121   >>    C2123132222131133131121131211113313231322331333133311211331323223313232212   <<    C21231322221311331311211312111133132313223313331333112113313232233132322123   >>      C21231322221311331311211312111133132313223313331333112113313232233132322122   >>