a-a a-b a-i aaa aab aai aan aao aap aas ab- aba abb abi abn abo abp abs ai- aia aib aii ain aio aip ais an- ana anb ani ann ano anp ans aoa aob aoi aon aoo aop aos ap- apa apb api apn apo app aps as- asa asb asi asn aso asp ass b-p baa bab bai ban bao bap bas bba bbb bbi bbn bbo bbp bbs bi- bia bib bii bin bio bip bis bna bnb bni bnn bno bnp bns boa bob boi bon boo bop bos bpa bpb bpi bpn bpo bpp bps bsa bsb bsi bsn bso bsp bss ia- iaa iab iai ian iao iap ias iba ibb ibi ibn ibo ibp ibs iia iib iii iin iio iip iis in- ina inb ini inn ino inp ins io- ioa iob ioi ion ioo iop ios ipa ipb ipi ipn ipo ipp ips is- isa isb isi isn iso isp iss n-i naa nab nai nan nao nap nas nba nbb nbi nbn nbo nbp nbs nia nib nii nin nio nip nis nna nnb nni nnn nno nnp nns no- noa nob noi non noo nop nos npa npb npi npn npo npp nps nsa nsb nsi nsn nso nsp nss o-i oaa oab oai oan oao oap oas ob- oba obb obi obn obo obp obs oia oib oii oin oio oip ois on- ona onb oni onn ono onp ons oo- ooa oob ooi oon ooo oop oos op- opa opb opi opn opo opp ops os- osa osb osi osn oso osp oss p-p paa pab pai pan pao pap pas pba pbb pbi pbn pbo pbp pbs pia pib pii pin pio pip pis pn- pna pnb pni pnn pno pnp pns poa pob poi pon poo pop pos ppa ppb ppi ppn ppo ppp pps ps- psa psb psi psn pso psp pss saa sab sai san sao sap sas sba sbb sbi sbn sbo sbp sbs sia sib sii sin sio sip sis sna snb sni snn sno snp sns soa sob soi son soo sop sos spa spb spi spn spo spp sps ss- ssa ssb ssi ssn sso ssp sss