a-a a-b a-c aaa aab aac aae aaf aao aas aau ab- aba abb abc abe abf abo abs abu ac- aca acb acc ace acf aco acs acu aea aeb aec aee aef aeo aes aeu af- afa afb afc afe aff afo afs afu aoa aob aoc aoe aof aoo aos aou as- asa asb asc ase asf aso ass asu au- aua aub auc aue auf auo aus b-u baa bab bac bae baf bao bas bau bba bbb bbc bbe bbf bbo bbs bbu bca bcb bcc bce bcf bco bcs bcu be- bea beb bec bee bef beo bes beu bfa bfb bfc bfe bff bfo bfs bfu boa bob boc boe bof boo bos bou bsa bsb bsc bse bsf bso bss bsu bua bub buc bue buf buo bus buu c-- caa cab cac cae caf cao cas cau cba cbb cbc cbe cbf cbo cbs cbu cca ccb ccc cce ccf cco ccs ccu ce- cea ceb cec cee cef ceo ces ceu cfa cfb cfc cfe cff cfo cfs cfu co- coa cob coc coe cof coo cos cou csa csb csc cse csf cso css csu cua cub cuc cue cuf cuo cus cuu eaa eab eac eae eaf eao eas eau eba ebb ebc ebe ebf ebo ebs ebu ec- eca ecb ecc ece ecf eco ecs ecu eea eeb eec eee eef eeo ees ef- efa efb efc efe eff efo efs eo- eoa eob eoc eoe eof eoo eos eou es- esa esb esc ese esf eso ess esu eu- eua eub euc eue euf eus faa fab fac fae faf fao fas fau fba fbb fbc fbe fbf fbo fbs fbu fca fcb fcc fce fcf fco fcs fcu fea feb fec fee fef feo fes feu ffa ffc ffe fff ffo ffs ffu foa fob foc foe fof foo fos fou fsa fsb fsc fse fsf fso fss fsu fua fub fue fuf fuo fus fuu oaa oab oac oae oaf oao oas oau ob- oba obb obc obe obf obo obs obu oc- oca ocb occ ocf oco ocs ocu oea oeb oec oee oef oeo oes of- ofa ofb ofc ofe off ofo ofs ofu oo- ooa oob ooc oof ooo oos os- osa osb osc ose osf oso oss osu ou- oua ouc oue ouf ouo ous saa sab sac sae saf sao sas sau sba sbb sbc sbe sbf sbo sbs sbu sca scb scc sce scf sco scs scu se- sea seb sec see sef seo ses seu sfa sfb sfc sfe sff sfo sfs sfu soa sob soc soe sof soo sos sou ss- ssa ssb ssc sse ssf sso sss ssu sua sub suc sue suf suo sus suu ua- uaa uab uac uae uaf uao uas uau uba ubb ubc ube ubf ubo ubs ubu uca ucb ucc uce ucf uco ucs ucu uea ueb uec uee uef ues ufa ufc ufe uff ufo ufs ufu uoa uob uoc uoe uoo uos usa usb usc use usf uso uss usu uua uuc uue uus uuu