a-a a-b a-i aaa aab aai aan aap aas ab- aba abb abi abn abp abs ai- aia aib aii ain aip ais an- ana anb ani ann anp ans ap- apa apb api apn app aps as- asa asb asi asn asp ass b-p baa bab bai ban bap bas bba bbb bbi bbn bbp bbs bi- bia bib bii bin bip bis bna bnb bni bnn bnp bns bpa bpb bpi bpn bpp bps bsa bsb bsi bsn bsp bss ia- iaa iab iai ian iap ias iba ibb ibi ibn ibp ibs iia iib iii iin iip iis in- ina inb ini inn inp ins ipa ipb ipi ipn ipp ips is- isa isb isi isn isp iss n-i naa nab nai nan nap nas nba nbb nbi nbn nbp nbs nia nib nii nin nip nis nna nnb nni nnn nnp nns npa npb npi npn npp nps nsa nsb nsi nsn nsp nss p-p paa pab pai pan pap pas pba pbb pbi pbn pbp pbs pia pib pii pin pip pis pn- pna pnb pni pnn pnp pns ppa ppb ppi ppn ppp pps ps- psa psb psi psn psp pss saa sab sai san sap sas sba sbb sbi sbn sbp sbs sia sib sii sin sip sis sna snb sni snn snp sns spa spb spi spn spp sps ss- ssa ssb ssi ssn ssp sss