-ic a-a a-b a-c a-i aaa aab aac aai aak aan aao aar aas ab- aba abb abc abi abk abn abo abr abs ac- aca acb acc aci ack acn aco acr acs ai- aia aib aic aii aik ain aio air ais aka akb akc aki akk akn ako akr aks an- ana anb anc ani ank ann ano anr ans aoa aob aoc aoi aok aon aoo aor aos ar- ara arb arc ari ark arn aro arr ars as- asa asb asc asi ask asn aso asr ass baa bab bac bai bak ban bao bar bas bba bbb bbc bbi bbk bbn bbo bbr bbs bca bcb bcc bci bck bcn bco bcr bcs bi- bia bib bic bii bik bin bio bir bis bka bkb bkc bkk bkn bko bkr bks bna bnb bnc bni bnk bnn bno bnr bns boa bob boc boi bok bon boo bor bos bra brb bri brk brn bro brr brs bsa bsb bsc bsi bsk bsn bso bsr bss c-- caa cab cac cai cak can cao car cas cba cbb cbc cbi cbk cbn cbo cbr cbs cca ccb ccc cci cck ccn cco ccr ccs ci- cia cib cic cii cik cin cio cir cis cka ckb ckc cki cko cks cn- cna cnb cnc cni cnn cno cnr cns co- coa cob coc coi cok con coo cor cos cra crb crc cri crk crn cro crr crs csa csb csc csi csk csn cso csr css ia- iaa iab iac iai ian iao iar ias iba ibb ibc ibi ibk ibn ibo ibr ibs ica icb icc ici ick icn ico icr ics iia iib iic iii iin iio iir iis ika ikb ikc iki ikk iko ikr iks in- ina inb inc ini ink inn ino inr ins io- ioa iob ioc ioi ion ioo ior ios ir- ira irb irc iri irk irn iro irr irs is- isa isb isc isi isk isn iso isr iss ka- kaa kab kac kai kak kan kao kar kas kba kbb kbc kbi kbk kbn kbo kbr kbs kca kcb kcc kci kck kcn kcr kcs kia kib kic kii kik kin kio kir kis kkb kkc kki kkk kkn kkr kks kn- kna knc kni knk knn kno knr koa kob koc koi kok kon koo kor kos kra krc kri krk krn kro krr krs ksa ksb ksc ksi ksk ksn kso ksr kss n-i naa nab nac nai nak nan nao nar nas nba nbb nbc nbi nbk nbn nbo nbr nbs nca ncb ncc nci nck ncn nco ncr ncs nia nib nic nii nik nin nio nir nis nka nkc nki nkk nkn nko nkr nks nna nnb nnc nni nnk nnn nno nns no- noa nob noc noi nok non noo nor nos nra nrb nrc nri nrk nrn nro nrr nrs nsa nsb nsc nsi nsk nsn nso nsr nss o-i oaa oab oac oai oak oan oao oar oas ob- oba obb obc obi obk obn obo obr obs oc- oca ocb occ oci ock ocn oco ocr ocs oia oib oic oii oik oin oio oir ois oka okb okc oki okk oko okr oks on- ona onb onc oni onk onn ono onr ons oo- ooa oob ooc ooi ook oon ooo oor oos or- ora orb orc ori ork orn oro orr ors os- osa osb osc osi osk osn oso osr oss ra- raa rab rac rai rak ran rao rar ras rba rbb rbc rbi rbk rbn rbo rbr rbs rca rcb rcc rci rcn rco rcr rcs ria rib ric rii rik rin rio rir ris rkb rkc rkk rko rks rna rnb rnc rni rnn rno rnr rns roa rob roc roi rok ron roo ror ros rra rrb rrc rri rrk rrn rrr rrs rsa rsb rsc rsi rsk rsn rso rsr rss saa sab sac sai sak san sao sar sas sba sbb sbc sbi sbk sbn sbo sbr sbs sca scb scc sci sck scn sco scr scs sia sib sic sii sik sin sio sir sis sk- ska skb skc ski skk sko skr sks sna snb snc sni snk snn sno snr sns soa sob soc soi sok son soo sor sos sr- sra srb src sri srk srn sro srr srs ss- ssa ssb ssc ssi ssk ssn sso ssr sss