a-a a-b a-c a-t aaa aab aac aao aas aat aau aay ab- aba abb abc abo abs abt abu aby ac- aca acb acc aco acs act acu acy aoa aob aoc aoo aos aot aou as- asa asb asc aso ass ast asu asy at- ata atb atc ato ats att atu au- aua aub auc auo aus aut ay- aya ayc ayo ays ayt ayu b-u baa bab bac bao bas bat bau bay bba bbb bbc bbo bbs bbt bbu bby bca bcb bcc bco bcs bct bcu bcy boa bob boc boo bos bot bou boy bsa bsb bsc bso bss bst bsu bsy bta btb btc bto bts btt btu bty bua bub buc buo bus but buu buy by- bya byc byo bys byt byu c-- caa cab cac cao cas cat cau cay cba cbb cbc cbo cbs cbt cbu cby cca ccb ccc cco ccs cct ccu co- coa cob coc coo cos cot cou coy csa csb csc cso css cst csu csy cta ctb ctc cto cts ctt ctu cty cua cub cuc cuo cus cut cuu cuy cya cyb cyc cyo cys cyt oaa oab oac oao oas oat oau ob- oba obb obc obo obs obt obu oby oc- oca ocb occ oco ocs oct ocu oo- ooa oob ooc ooo oos oot os- osa osb osc oso oss ost osu ot- ota otb otc oto ots ott otu ou- oua ouc ouo ous out oya oyo oys saa sab sac sao sas sat sau say sba sbb sbc sbo sbs sbt sbu sby sca scb scc sco scs sct scu soa sob soc soo sos sot sou soy ss- ssa ssb ssc sso sss sst ssu sta stb stc sto sts stt stu sty sua sub suc suo sus sut suu suy sy- sya syb syc sys syt syu taa tab tac tao tas tat tau tay tba tbb tbc tbo tbs tbt tbu tca tcb tcc tco tcs tct tcu to- toa tob toc too tos tot tou toy tsa tsb tsc tso tss tst tsu tsy tta ttb ttc tto tts ttt ttu tty tua tub tuc tuo tus tut tuu tuy tya tyc tyo tys tyt ua- uaa uab uac uao uas uat uau uay uba ubb ubc ubo ubs ubt ubu uby uca ucb ucc uco ucs uct ucu uoa uob uoc uoo uos uot usa usb usc uso uss ust usu uta utb utc uto uts utt utu uty uua uuc uus uut uuu uyc uyo uys uyu yaa yab yac yao yas yat yau yay ybc ybs yby yca ycc yco ycs ycu ycy yob yoc yoo yos yot you yoy ysa ysb ysc yso yss yst ysu ysy yta ytc yto yts ytt ytu yua yuo yus yut yuu yuy yyb yyc yys yyt yyu yyy