-er a-a a-c aaa aac aae aak aar aav ac- aca acc ace ack acr acv aea aec aee aek aer aev aka akc ake akk akr akv ar- ara arc are ark arr arv av- ava avc ave avk avr c-- caa cac cae cak car cav cca ccc cce cck ccr ccv ce- cea cec cee cek cer cev cka ckc cra crc cre crk crr crv cva cvc cve cvk cvr cvv eaa eac eae eak ear eav ec- eca ecc ece eck ecr ecv eea eec eee eek eer eev eka ekc eke ekr ekv era erc ere erk err erv eva evc eve evr evv ka- kaa kac kae kak kar kav kca kcc kce kck kcr ke- kea kec kee kek ker kev kkc kke kkk kkr kkv kra krc krk krr krv kva kvk kvr kvv ra- raa rac rae rak rar rav rca rcc rce rcr rcv re- rea rec ree rek rer rev rkc rke rkk rkv rra rrc rrk rrr rva rvc rve rvr rvv v-a v-e vaa vac vae vak var vav vca vcc vce vcr vea vec vee vek ver vka vra vrc vre vrk vrr vva vvc vvr vvv