a-a a-b a-c aaa aab aac aae aah aao aas ab- aba abb abc abe abh abo abs ac- aca acb acc ace ach aco acs aea aeb aec aee aeh aeo aes aha ahb ahc ahe ahh aho ahs aoa aob aoc aoe aoh aoo aos as- asa asb asc ase ash aso ass baa bab bac bae bah bao bas bba bbb bbc bbe bbh bbo bbs bca bcb bcc bce bch bco bcs be- bea beb bec bee beh beo bes bha bhb bhc bhe bhh bho bhs boa bob boc boe boh boo bos bsa bsb bsc bse bsh bso bss c-- caa cab cac cae cah cao cas cba cbb cbc cbe cbh cbo cbs cca ccb ccc cce cch cco ccs ce- cea ceb cec cee ceh ceo ces ch- cha chb chc che chh cho chs co- coa cob coc coe coh coo cos csa csb csc cse csh cso css eaa eab eac eae eah eao eas eba ebb ebc ebe ebh ebo ebs ec- eca ecb ecc ece ech eco ecs eea eeb eec eee eeo ees eha ehb ehc ehe ehh eho ehs eo- eoa eob eoc eoe eoh eoo eos es- esa esb esc ese esh eso ess haa hab hac hae hah hao has hba hbb hbc hbe hbh hbo hbs hca hcb hcc hce hch hco hcs he- hea heb hec hee heh heo hes hha hhb hhc hhe hhh hho hhs hoa hob hoc hoe hoh hoo hos hsa hsb hsc hse hsh hss oaa oab oac oae oah oao oas ob- oba obb obc obe obh obo obs oc- oca ocb occ och oco ocs oea oeb oec oee oeh oeo oes oha ohc ohe ohh oho ohs oo- ooa oob ooc ooh ooo oos os- osa osb osc ose osh oso oss saa sab sac sae sah sao sas sba sbb sbc sbe sbh sbo sbs sca scb scc sce sch sco scs se- sea seb sec see seh seo ses sh- sha shb shc she shh sho shs soa sob soc soe soh soo sos ss- ssa ssb ssc sse ssh sso sss