a-a a-b aaa aab aah aan aao aas ab- aba abb abh abn abo abs aha ahb ahh ahn aho ahs an- ana anb anh ann ano ans aoa aob aoh aon aoo aos as- asa asb ash asn aso ass baa bab bah ban bao bas bba bbb bbh bbn bbo bbs bha bhb bhh bho bhs bna bnb bnn bno bns boa bob boh bon boo bos bsa bsb bsh bsn bso bss haa hab hah han hao has hba hbb hbh hbn hbo hbs hha hhb hhh hhn hho hhs hna hnb hnh hnn hno hns hoa hob hoh hon hoo hos hsa hsb hsh hsn hss naa nab nah nan nao nas nba nbb nbn nbo nbs nha nhb nhh nhn nhs nna nnb nnh nnn nno nns no- noa nob noh non noo nos nsa nsb nsh nsn nso nss oaa oab oah oan oao oas ob- oba obb obh obn obo obs oha ohh ohn oho ohs on- ona onb onh onn ono ons oo- ooa oob ooh oon ooo oos os- osa osb osh osn oso oss saa sab sah san sao sas sba sbb sbh sbn sbo sbs sh- sha shb shh shn sho shs sna snb snn sno sns soa sob soh son soo sos ss- ssa ssb ssh ssn sso sss