a-a a-b a-c a-z aaa aab aac aaf aah aar aaz ab- aba abb abc abf abh abr abz ac- aca acb acc acf ach acr acz af- afa afb afc aff afh afr afz aha ahb ahc ahf ahh ahr ahz ar- ara arb arc arf arh arr arz az- aza azb azf azz baa bab bac baf bah bar baz bba bbb bbc bbf bbh bbr bca bcb bcc bcf bch bcr bcz bfa bfb bfc bff bfh bfr bfz bha bhb bhc bhf bhh bhr bra brb brf brh brr brz bza bzf bzh bzr bzz c-- caa cab cac caf cah car caz cba cbb cbc cbf cbh cbr cbz cca ccb ccc ccf cch ccr ccz cfa cfb cfc cff cfh cfr cfz ch- cha chb chc chf chh chr chz cra crb crc crf crh crr crz cz- czc faa fab fac faf fah far faz fba fbb fbc fbf fbh fbr fca fcb fcc fcf fcr fcz ffa ffc fff ffh ffr ffz fha fhb fhc fhf fhh fhr fra frb frc frf frh frr fzh haa hab hac haf hah har haz hba hbb hbc hbf hbh hbr hbz hca hcb hcc hcf hch hcr hfa hfb hfc hff hfh hfr hha hhb hhc hhf hhh hhr hhz hr- hra hrb hrc hrf hrh hrr hrz ra- raa rab rac raf rah rar raz rba rbb rbc rbf rbh rbr rca rcb rcc rcf rch rcr rfa rfb rfc rff rfh rfr rfz rh- rha rhb rhc rhf rhh rhr rra rrb rrc rrf rrh rrr rza rzb zaa zab zac zaf zah zar zaz zbb zbc zbr zfa zfc zfr zha zhc zhr zrh zzr zzz