-er a-a a-b a-i aaa aab aae aai aak aan aao aap aar ab- aba abb abe abi abk abn abo abp abr aea aeb aee aei aek aen aeo aep aer ai- aia aib aie aii aik ain aio aip air aka akb ake aki akk akn ako akp akr an- ana anb ane ani ank ann ano anp anr aoa aob aoe aoi aok aon aoo aop aor ap- apa apb ape api apk apn apo app apr ar- ara arb are ari ark arn aro arp arr b-p baa bab bae bai bak ban bao bap bar bba bbb bbe bbi bbk bbn bbo bbp bbr be- bea beb bee bei bek ben beo bep ber bi- bia bib bie bii bik bin bio bip bir bka bkb bke bkk bkn bko bkp bkr bna bnb bne bni bnk bnn bno bnp bnr boa bob boe boi bok bon boo bop bor bpa bpb bpe bpi bpn bpo bpp bpr bra brb bre bri brk brn bro brp brr eaa eab eae eai eak ean eao eap ear eba ebb ebe ebi ebk ebn ebo ebp ebr eea eeb eee eek een eeo eep eer eia eib eie eii eik ein eio eip eir eka ekb eke eki eko ekp ekr en- ena enb ene eni enk enn eno enp enr eo- eoa eob eoe eoi eok eon eoo eop eor ep- epa epb epe epi epn epo epp epr era erb ere eri erk ern ero erp err ia- iaa iab iae iai ian iao iap iar iba ibb ibe ibi ibk ibn ibo ibp ibr ie- iea iee iei iek ien iep ier iia iib iie iii iin iio iip iir ika ikb ike iki ikk iko ikr in- ina inb ine ini ink inn ino inp inr io- ioa iob ioe ioi ion ioo iop ior ipa ipb ipe ipi ipn ipo ipp ipr ir- ira irb ire iri irk irn iro irp irr ka- kaa kab kae kai kak kan kao kap kar kba kbb kbe kbi kbk kbn kbo kbp kbr ke- kea keb kee kei kek ken keo kep ker kia kib kie kii kik kin kio kip kir kkb kke kki kkk kkn kkp kkr kn- kna kne kni knk knn kno knp knr koa kob koe koi kok kon koo kop kor kpa kpe kpi kpk kpn kpo kpp kpr kra kri krk krn kro krp krr n-i naa nab nae nai nak nan nao nap nar nba nbb nbe nbi nbk nbn nbo nbp nbr ne- nea neb nee nei nek nen neo nep ner nia nib nie nii nik nin nio nip nir nka nke nki nkk nkn nko nkp nkr nna nnb nne nni nnk nnn nno nnp no- noa nob noe noi nok non noo nop nor npa npb npe npi npn npo npp npr nra nrb nre nri nrk nrn nro nrp nrr o-i oaa oab oae oai oak oan oao oap oar ob- oba obb obe obi obk obn obo obp obr oea oeb oee oei oen oeo oep oer oia oib oie oii oik oin oio oip oir oka okb oke oki okk oko okp okr on- ona onb one oni onk onn ono onp onr oo- ooa oob ooi ook oon ooo oop oor op- opa opb ope opi opk opn opo opp opr or- ora orb ore ori ork orn oro orp orr p-p paa pab pae pai pak pan pao pap par pba pbb pbe pbi pbk pbn pbo pbp pbr pea peb pee pei pek pen peo pep per pia pib pie pii pik pin pio pip pir pka pkb pke pki pkn pko pkp pkr pn- pna pnb pne pni pnk pnn pno pnp pnr poa pob poe poi pok pon poo pop por ppa ppb ppe ppi ppk ppn ppo ppp ppr pra prb pre pri prk prn pro prp prr ra- raa rab rae rai rak ran rao rap rar rba rbb rbe rbi rbk rbn rbo rbp rbr re- rea reb ree rei rek ren reo rep rer ria rib rie rii rik rin rio rip rir rkb rke rkk rko rkp rna rnb rni rnn rno rnp rnr roa rob roe roi rok ron roo rop ror rpa rpb rpe rpi rpk rpn rpo rpp rpr rra rrb rri rrk rrn rrp rrr