a-a a-b a-i aaa aab aai aan aap aar aas ab- aba abb abi abn abp abr abs ai- aia aib aii ain aip air ais an- ana anb ani ann anp anr ans ap- apa apb api apn app apr aps ar- ara arb ari arn arp arr ars as- asa asb asi asn asp asr ass b-p baa bab bai ban bap bar bas bba bbb bbi bbn bbp bbr bbs bi- bia bib bii bin bip bir bis bna bnb bni bnn bnp bnr bns bpa bpb bpi bpn bpp bpr bps bra brb bri brn brp brr brs bsa bsb bsi bsn bsp bsr bss ia- iaa iab iai ian iap iar ias iba ibb ibi ibn ibp ibr ibs iia iib iii iin iip iir iis in- ina inb ini inn inp inr ins ipa ipb ipi ipn ipp ipr ips ir- ira irb iri irn irp irr irs is- isa isb isi isn isp isr iss n-i naa nab nai nan nap nar nas nba nbb nbi nbn nbp nbr nbs nia nib nii nin nip nir nis nna nnb nni nnn nnp nns npa npb npi npn npp npr nps nra nrb nri nrn nrp nrr nrs nsa nsb nsi nsn nsp nsr nss p-p paa pab pai pan pap par pas pba pbb pbi pbn pbp pbr pbs pia pib pii pin pip pir pis pn- pna pnb pni pnn pnp pnr pns ppa ppb ppi ppn ppp ppr pps pra prb pri prn prp prr prs ps- psa psb psi psn psp psr pss ra- raa rab rai ran rap rar ras rba rbb rbi rbn rbp rbr rbs ria rib rii rin rip rir ris rna rnb rni rnn rnp rnr rns rpa rpb rpi rpn rpp rpr rps rra rrb rri rrn rrp rrr rrs rsa rsb rsi rsn rsp rsr rss saa sab sai san sap sar sas sba sbb sbi sbn sbp sbr sbs sia sib sii sin sip sir sis sna snb sni snn snp snr sns spa spb spi spn spp spr sps sr- sra srb sri srn srp srr srs ss- ssa ssb ssi ssn ssp ssr sss