a-a a-b a-i aaa aab aai aan aao aap aar aas ab- aba abb abi abn abo abp abr abs ai- aia aib aii ain aio aip air ais an- ana anb ani ann ano anp anr ans aoa aob aoi aon aoo aop aor aos ap- apa apb api apn apo app apr aps ar- ara arb ari arn aro arp arr ars as- asa asb asi asn aso asp asr ass b-p baa bab bai ban bao bap bar bas bba bbb bbi bbn bbo bbp bbr bbs bi- bia bib bii bin bio bip bir bis bna bnb bni bnn bno bnp bnr bns boa bob boi bon boo bop bor bos bpa bpb bpi bpn bpo bpp bpr bps bra brb bri brn bro brp brr brs bsa bsb bsi bsn bso bsp bsr bss ia- iaa iab iai ian iao iap iar ias iba ibb ibi ibn ibo ibp ibr ibs iia iib iii iin iio iip iir iis in- ina inb ini inn ino inp inr ins io- ioa iob ioi ion ioo iop ior ios ipa ipb ipi ipn ipo ipp ipr ips ir- ira irb iri irn iro irp irr irs is- isa isb isi isn iso isp isr iss n-i naa nab nai nan nao nap nar nas nba nbb nbi nbn nbo nbp nbr nbs nia nib nii nin nio nip nir nis nna nnb nni nnn nno nnp nns no- noa nob noi non noo nop nor nos npa npb npi npn npo npp npr nps nra nrb nri nrn nro nrp nrr nrs nsa nsb nsi nsn nso nsp nsr nss o-i oaa oab oai oan oao oap oar oas ob- oba obb obi obn obo obp obr obs oia oib oii oin oio oip oir ois on- ona onb oni onn ono onp onr ons oo- ooa oob ooi oon ooo oop oor oos op- opa opb opi opn opo opp opr ops or- ora orb ori orn oro orp orr ors os- osa osb osi osn oso osp osr oss p-p paa pab pai pan pao pap par pas pba pbb pbi pbn pbo pbp pbr pbs pia pib pii pin pio pip pir pis pn- pna pnb pni pnn pno pnp pnr pns poa pob poi pon poo pop por pos ppa ppb ppi ppn ppo ppp ppr pps pra prb pri prn pro prp prr prs ps- psa psb psi psn pso psp psr pss ra- raa rab rai ran rao rap rar ras rba rbb rbi rbn rbo rbp rbr rbs ria rib rii rin rio rip rir ris rna rnb rni rnn rno rnp rnr rns roa rob roi ron roo rop ror ros rpa rpb rpi rpn rpo rpp rpr rps rra rrb rri rrn rrp rrr rrs rsa rsb rsi rsn rso rsp rsr rss saa sab sai san sao sap sar sas sba sbb sbi sbn sbo sbp sbr sbs sia sib sii sin sio sip sir sis sna snb sni snn sno snp snr sns soa sob soi son soo sop sor sos spa spb spi spn spo spp spr sps sr- sra srb sri srn sro srp srr srs ss- ssa ssb ssi ssn sso ssp ssr sss