c-- ccc ccd cce cck cco ccs cdc cdd cde cdk cdo cds ce- cec ced cee cek ceo ces ckc ckd cko cks co- coc cod coe cok coo cos csc csd cse csk cso css dcc dcd dce dck dco dcs ddc ddd dde ddk ddo dds de- dec ded dee dek deo des dkc dke dkk dko dks doc dod doe dok doo dos dsc dsd dse dsk dso dss ec- ecc ecd ece eck eco ecs ed- edc edd ede edk edo eds eec eed eee eek eeo ees ekc ekd eke eko eks eo- eoc eod eoe eok eoo eos es- esc esd ese esk eso ess kcc kcd kce kck kcs kdc kde kdk kdo kds ke- kec ked kee kek keo kes kkc kke kkk kks koc kod koe kok koo kos ksc ksd kse ksk kso kss oc- occ ocd ock oco ocs odc odd ode odo ods oec oed oee oeo oes okc okd oke okk oko oks oo- ooc ood ook ooo oos os- osc osd ose osk oso oss scc scd sce sck sco scs sdc sdd sde sdk sdo sds se- sec sed see sek seo ses sk- skc skd ske skk sko sks soc sod soe sok soo sos ss- ssc ssd sse ssk sso sss