-er a-a a-c aaa aac aae aak aao aar aau ac- aca acc ace ack aco acr acu aea aec aee aek aeo aer aeu aka akc ake akk ako akr aku aoa aoc aoe aok aoo aor aou ar- ara arc are ark aro arr aru au- aua auc aue auk auo aur c-- caa cac cae cak cao car cau cca ccc cce cck cco ccr ccu ce- cea cec cee cek ceo cer ceu cka ckc cko co- coa coc coe cok coo cor cou cra crc cre crk cro crr cru cua cuc cue cuk cuo cur cuu eaa eac eae eak eao ear eau ec- eca ecc ece eck eco ecr ecu eea eec eee eek eeo eer eka ekc eke eko ekr eku eo- eoa eoc eoe eok eoo eor eou era erc ere erk ero err eru eu- eua euc eue eur ka- kaa kac kae kak kao kar kau kca kcc kce kck kcr kcu ke- kea kec kee kek keo ker kkc kke kkk kkr kku koa koc koe kok koo kor kou kra krc krk kro krr kru kuc kue kuk kur kuu oaa oac oae oak oao oar oau oc- oca occ ock oco ocr ocu oea oec oee oeo oer oka okc oke okk oko okr oku oo- ooa ooc ook ooo oor or- ora orc ore ork oro orr oru ou- oua ouc oue ouk ouo our ra- raa rac rae rak rao rar rau rca rcc rce rco rcr rcu re- rea rec ree rek reo rer reu rkc rke rkk rko rku roa roc roe rok roo ror rou rra rrc rrk rrr rru rua ruc rue ruk ruo rur ruu ua- uaa uac uae uak uao uar uau uca ucc uce uck uco ucr ucu uea uec uee uer uka ukc uke ukk ukr uku uoa uoc uoe uok uoo uor ur- ura urc ure urk uro urr uru uua uuc uue uur uuu