-er a-a a-c aaa aac aae aag aak aan aap aar ac- aca acc ace acg ack acn acp acr aea aec aee aeg aek aen aep aer ag- aga agc age agg agk agn agp agr aka akc ake akg akk akn akp akr an- ana anc ane ang ank ann anp anr ap- apa apc ape apg apk apn app apr ar- ara arc are arg ark arn arp arr c-- caa cac cae cag cak can cap car cca ccc cce ccg cck ccn ccp ccr ce- cea cec cee ceg cek cen cep cer cga cgc cge cgg cgn cgp cgr cka ckc cn- cna cnc cne cng cnn cnp cnr cpa cpc cpe cpg cpk cpn cpp cpr cra crc cre crg crk crn crp crr eaa eac eae eag eak ean eap ear ec- eca ecc ece ecg eck ecn ecr eea eec eee eeg eek een eep eer ega egc ege egg egn egp egr eka ekc eke ekg ekp ekr en- ena enc ene eng enk enn enp enr ep- epa epc epe epg epn epp epr era erc ere erg erk ern erp err g-p gaa gac gae gag gak gan gap gar gca gcc gce gcg gck gcn gcp gcr ge- gea gec gee geg gek gen gep ger gga ggc ggg ggn ggp ggr gka gkn gkp gna gnc gne gnn gnp gnr gpa gpc gpe gpg gpk gpn gpp gpr gra grc gre grg grk grn grp grr ka- kaa kac kae kag kak kan kap kar kca kcc kce kcg kck kcn kcp kcr ke- kea kec kee keg kek ken kep ker kga kgc kgp kkc kke kkk kkn kkp kkr kn- kna knc kne kng knk knn knp knr kpa kpc kpe kpk kpn kpp kpr kra krc krg krk krn krp krr naa nac nae nag nak nan nap nar nca ncc nce ncg nck ncn ncp ncr ne- nea nec nee neg nek nen nep ner nga ngc nge ngg ngk ngn ngp nka nkc nke nkk nkn nkp nkr nna nnc nne nng nnk nnn nnp npa npc npe npg npn npp npr nra nrc nre nrg nrk nrn nrp nrr p-p paa pac pae pag pak pan pap par pca pcc pce pcg pck pcn pcp pcr pea pec pee peg pek pen pep per pga pgc pge pgg pgk pgn pgp pgr pka pkc pke pkg pkn pkp pkr pn- pna pnc pne png pnk pnn pnp pnr ppa ppc ppe ppg ppk ppn ppp ppr pra prc pre prg prk prn prp prr ra- raa rac rae rag rak ran rap rar rca rcc rce rcg rcn rcp rcr re- rea rec ree reg rek ren rep rer rga rgc rge rgg rgk rgn rgp rgr rkc rke rkg rkk rkp rna rnc rng rnn rnp rnr rpa rpc rpe rpg rpk rpn rpp rpr rra rrc rrg rrk rrn rrp rrr