-er a-a a-c a-t aaa aac aae aak aap aar aat ac- aca acc ace ack acp acr act aea aec aee aek aep aer aet aka akc ake akk akp akr ap- apa apc ape apk app apr apt ar- ara arc are ark arp arr art at- ata atc ate atp atr att c-- caa cac cae cak cap car cat cca ccc cce cck ccp ccr cct ce- cea cec cee cek cep cer cet cka ckc ckt cpa cpc cpe cpk cpp cpr cpt cra crc cre crk crp crr crt cta ctc cte ctk ctp ctr ctt eaa eac eae eak eap ear eat ec- eca ecc ece eck ecr ect eea eec eee eek eep eer eet eka ekc eke ekp ekr ekt ep- epa epc epe epp epr ept era erc ere erk erp err ert eta etc ete etk etp etr ett k-t ka- kaa kac kae kak kap kar kat kca kcc kce kck kcp kcr kct ke- kea kec kee kek kep ker ket kkc kke kkk kkp kkr kkt kpa kpc kpe kpk kpp kpr kpt kra krc krk krp krr krt kta ktc kte ktk ktp ktr ktt p-p paa pac pae pak pap par pat pca pcc pce pck pcp pcr pct pea pec pee pek pep per pet pka pkc pke pkp pkr pkt ppa ppc ppe ppk ppp ppr ppt pra prc pre prk prp prr prt pt- pta ptc pte ptk ptp ptr ptt ra- raa rac rae rak rap rar rat rca rcc rce rcp rcr rct re- rea rec ree rek rep rer ret rkc rke rkk rkp rkt rpa rpc rpe rpk rpp rpr rpt rra rrc rrk rrp rrr rrt rta rtc rte rtk rtp rtr rtt taa tac tae tak tap tar tat tca tcc tce tck tcp tcr tct te- tea tec tee tek tep ter tet tka tkc tke tkk tkp tkr tkt tpa tpc tpe tpk tpp tpr tpt tra trc tre trk trp trr trt tta ttc tte ttk ttp ttr ttt