a-a a-b a-i aaa aab aai aan aap aar ab- aba abb abi abn abp abr ai- aia aib aii ain aip air an- ana anb ani ann anp anr ap- apa apb api apn app apr ar- ara arb ari arn arp arr b-p baa bab bai ban bap bar bba bbb bbi bbn bbp bbr bi- bia bib bii bin bip bir bna bnb bni bnn bnp bnr bpa bpb bpi bpn bpp bpr bra brb bri brn brp brr ia- iaa iab iai ian iap iar iba ibb ibi ibn ibp ibr iia iib iii iin iip iir in- ina inb ini inn inp inr ipa ipb ipi ipn ipp ipr ir- ira irb iri irn irp irr n-i naa nab nai nan nap nar nba nbb nbi nbn nbp nbr nia nib nii nin nip nir nna nnb nni nnn nnp npa npb npi npn npp npr nra nrb nri nrn nrp nrr p-p paa pab pai pan pap par pba pbb pbi pbn pbp pbr pia pib pii pin pip pir pn- pna pnb pni pnn pnp pnr ppa ppb ppi ppn ppp ppr pra prb pri prn prp prr ra- raa rab rai ran rap rar rba rbb rbi rbn rbp rbr ria rib rii rin rip rir rna rnb rni rnn rnp rnr rpa rpb rpi rpn rpp rpr rra rrb rri rrn rrp rrr