c-- ccc ccd cce cck ccs cdc cdd cde cdk cds ce- cec ced cee cek ces ckc ckd cks csc csd cse csk css dcc dcd dce dck dcs ddc ddd dde ddk dds de- dec ded dee dek des dkc dke dkk dks dsc dsd dse dsk dss ec- ecc ecd ece eck ecs ed- edc edd ede edk eds eec eed eee eek ees ekc ekd eke eks es- esc esd ese esk ess kcc kcd kce kck kcs kdc kde kdk kds ke- kec ked kee kek kes kkc kke kkk kks ksc ksd kse ksk kss scc scd sce sck scs sdc sdd sde sdk sds se- sec sed see sek ses sk- skc skd ske skk sks ss- ssc ssd sse ssk sss