c-- ccc cce cck cco ccv ce- cec cee cek ceo cev ckc cko co- coc coe cok coo cov cvc cve cvk cvo cvv ec- ecc ece eck eco ecv eec eee eek eeo eev ekc eke eko ekv eo- eoc eoe eok eoo evc eve evo evv kcc kce kck ke- kec kee kek keo kev kkc kke kkk kkv koc koe kok koo kvk kvo kvv oc- occ ock oco ocv oec oee oeo okc oke okk oko oo- ooc ook ooo oov ov- ovc ove ovo ovv v-e vcc vce vco vec vee vek veo voc voe vok voo vov vvc vvo vvv