a-a a-b a-c aaa aab aac aah aak aao aas aau ab- aba abb abc abh abk abo abs abu ac- aca acb acc ach ack aco acs acu aha ahb ahc ahh ahk aho ahs ahu aka akb akc akh akk ako aks aku aoa aob aoc aoh aok aoo aos aou as- asa asb asc ash ask aso ass asu au- aua aub auc auh auk auo aus b-u baa bab bac bah bak bao bas bau bba bbb bbc bbh bbk bbo bbs bbu bca bcb bcc bch bck bco bcs bcu bha bhb bhc bhh bhk bho bhs bhu bka bkb bkc bkk bko bks boa bob boc boh bok boo bos bou bsa bsb bsc bsh bsk bso bss bsu bua bub buc buh buk buo bus buu c-- caa cab cac cah cak cao cas cau cba cbb cbc cbh cbk cbo cbs cbu cca ccb ccc cch cck cco ccs ccu ch- cha chb chc chh chk cho chs chu cka ckb ckc ckh cko cks co- coa cob coc coh cok coo cos cou csa csb csc csh csk cso css csu cua cub cuc cuh cuk cuo cus cuu haa hab hac hah hak hao has hau hba hbb hbc hbh hbk hbo hbs hbu hca hcb hcc hch hck hco hcs hha hhb hhc hhh hhk hho hhs hhu hka hkb hkh hkk hko hks hku hoa hob hoc hoh hok hoo hos hou hsa hsb hsc hsh hsk hss hsu hua hub huc huh huk huo hus huu ka- kaa kab kac kah kak kao kas kau kba kbb kbc kbh kbk kbo kbs kbu kca kcb kcc kch kck kcs kcu kha khh khk kho khs khu kkb kkc kkh kkk kks kku koa kob koc koh kok koo kos kou ksa ksb ksc ksh ksk kso kss ksu kub kuc kuh kuk kus kuu oaa oab oac oah oak oao oas oau ob- oba obb obc obh obk obo obs obu oc- oca ocb occ och ock oco ocs ocu oha ohc ohh oho ohs ohu oka okb okc okk oko oks oku oo- ooa oob ooc ooh ook ooo oos os- osa osb osc osh osk oso oss osu ou- oua ouc ouh ouk ouo ous saa sab sac sah sak sao sas sau sba sbb sbc sbh sbk sbo sbs sbu sca scb scc sch sck sco scs scu sh- sha shb shc shh shk sho shs shu sk- ska skb skc skh skk sko sks sku soa sob soc soh sok soo sos sou ss- ssa ssb ssc ssh ssk sso sss ssu sua sub suc suh suk suo sus suu ua- uaa uab uac uah uak uao uas uau uba ubb ubc ubh ubk ubo ubs ubu uca ucb ucc uch uck uco ucs ucu uha uhb uhc uhh uho uhs uhu uka ukb ukc ukk uku uoa uob uoc uok uoo uos usa usb usc ush usk uso uss usu uua uuc uus uuu