-er a-a a-b a-i aaa aab aae aai aak aan aap aar ab- aba abb abe abi abk abn abp abr aea aeb aee aei aek aen aep aer ai- aia aib aie aii aik ain aip air aka akb ake aki akk akn akp akr an- ana anb ane ani ank ann anp anr ap- apa apb ape api apk apn app apr ar- ara arb are ari ark arn arp arr b-p baa bab bae bai bak ban bap bar bba bbb bbe bbi bbk bbn bbp bbr be- bea beb bee bei bek ben bep ber bi- bia bib bie bii bik bin bip bir bka bkb bke bkk bkn bkp bkr bna bnb bne bni bnk bnn bnp bnr bpa bpb bpe bpi bpn bpp bpr bra brb bre bri brk brn brp brr eaa eab eae eai eak ean eap ear eba ebb ebe ebi ebk ebn ebp ebr eea eeb eee eek een eep eer eia eib eie eii eik ein eip eir eka ekb eke eki ekp ekr en- ena enb ene eni enk enn enp enr ep- epa epb epe epi epn epp epr era erb ere eri erk ern erp err ia- iaa iab iae iai ian iap iar iba ibb ibe ibi ibk ibn ibp ibr ie- iea iee iei iek ien iep ier iia iib iie iii iin iip iir ika ikb ike iki ikk ikr in- ina inb ine ini ink inn inp inr ipa ipb ipe ipi ipn ipp ipr ir- ira irb ire iri irk irn irp irr ka- kaa kab kae kai kak kan kap kar kba kbb kbe kbi kbk kbn kbp kbr ke- kea keb kee kei kek ken kep ker kia kib kie kii kik kin kip kir kkb kke kki kkk kkn kkp kkr kn- kna kne kni knk knn knp knr kpa kpe kpi kpk kpn kpp kpr kra kri krk krn krp krr n-i naa nab nae nai nak nan nap nar nba nbb nbe nbi nbk nbn nbp nbr ne- nea neb nee nei nek nen nep ner nia nib nie nii nik nin nip nir nka nke nki nkk nkn nkp nkr nna nnb nne nni nnk nnn nnp npa npb npe npi npn npp npr nra nrb nre nri nrk nrn nrp nrr p-p paa pab pae pai pak pan pap par pba pbb pbe pbi pbk pbn pbp pbr pea peb pee pei pek pen pep per pia pib pie pii pik pin pip pir pka pkb pke pki pkn pkp pkr pn- pna pnb pne pni pnk pnn pnp pnr ppa ppb ppe ppi ppk ppn ppp ppr pra prb pre pri prk prn prp prr ra- raa rab rae rai rak ran rap rar rba rbb rbe rbi rbk rbn rbp rbr re- rea reb ree rei rek ren rep rer ria rib rie rii rik rin rip rir rkb rke rkk rkp rna rnb rni rnn rnp rnr rpa rpb rpe rpi rpk rpn rpp rpr rra rrb rri rrk rrn rrp rrr