a-a a-b a-i a-z aaa aab aai aar aas aaz ab- aba abb abi abr abs abz ai- aia aib aii air ais aiz ar- ara arb ari arr ars arz as- asa asb asi asr ass asz az- aza azb azi azs azz baa bab bai bar bas baz bba bbb bbi bbr bbs bi- bia bib bii bir bis biz bra brb bri brr brs brz bsa bsb bsi bsr bss bza bzr bzs bzz ia- iaa iab iai iar ias iaz iba ibb ibi ibr ibs ibz iia iib iii iir iis ir- ira irb iri irr irs is- isa isb isi isr iss iza izi izz ra- raa rab rai rar ras raz rba rbb rbi rbr rbs ria rib rii rir ris riz rra rrb rri rrr rrs rsa rsb rsi rsr rss rza rzb saa sab sai sar sas saz sba sbb sbi sbr sbs sia sib sii sir sis sr- sra srb sri srr srs ss- ssa ssb ssi ssr sss ssz sza szi szr zaa zab zai zar zas zaz zbb zbr zbs zia zib zir zis ziz zrs zsa zsi zsz zzr zzs zzz