a-a a-b a-c a-t aaa aab aac aaf aak aas aat aau ab- aba abb abc abf abk abs abt abu ac- aca acb acc acf ack acs act acu af- afa afb afc aff afk afs aft afu aka akb akc akk aks aku as- asa asb asc asf ask ass ast asu at- ata atb atc atf ats att atu au- aua aub auc auf auk aus aut b-u baa bab bac baf bak bas bat bau bba bbb bbc bbf bbk bbs bbt bbu bca bcb bcc bcf bck bcs bct bcu bfa bfb bfc bff bfs bft bfu bka bkb bkc bkf bkk bks bkt bsa bsb bsc bsf bsk bss bst bsu bta btb btc btf btk bts btt btu bua bub buc buf buk bus but buu c-- caa cab cac caf cak cas cat cau cba cbb cbc cbf cbk cbs cbt cbu cca ccb ccc ccf cck ccs cct ccu cfa cfb cfc cff cfk cfs cft cfu cka ckb ckc cks ckt csa csb csc csf csk css cst csu cta ctb ctc ctf ctk cts ctt ctu cua cub cuc cuf cuk cus cut cuu faa fab fac faf fak fas fat fau fba fbb fbc fbf fbk fbs fbt fbu fca fcb fcc fcf fck fcs fct fcu ffa ffc fff ffk ffs fft ffu fka fkb fkc fkf fkk fkt fsa fsb fsc fsf fsk fss fst fsu fta ftb ftc ftf ftk fts ftt ftu fua fub fuf fuk fus fut fuu k-t ka- kaa kab kac kaf kak kas kat kau kba kbb kbc kbf kbk kbs kbu kca kcb kcc kck kcs kct kcu kfa kfc kff kfs kfu kkb kkc kkk kks kkt kku ksa ksb ksc ksf ksk kss kst ksu kta ktb ktc ktf ktk kts ktt ktu kub kuc kuk kus kut kuu saa sab sac saf sak sas sat sau sba sbb sbc sbf sbk sbs sbt sbu sca scb scc scf sck scs sct scu sfa sfb sfc sff sfk sfs sft sfu sk- ska skb skc skf skk sks skt sku ss- ssa ssb ssc ssf ssk sss sst ssu sta stb stc stf stk sts stt stu sua sub suc suf suk sus sut suu taa tab tac taf tak tas tat tau tba tbb tbc tbf tbk tbs tbt tbu tca tcb tcc tcf tck tcs tct tcu tfa tfb tfc tff tfk tfs tft tfu tka tkb tkc tkk tks tkt tsa tsb tsc tsf tsk tss tst tsu tta ttb ttc ttf ttk tts ttt ttu tua tub tuc tuf tuk tus tut tuu ua- uaa uab uac uaf uak uas uat uau uba ubb ubc ubf ubk ubs ubt ubu uca ucb ucc ucf uck ucs uct ucu ufa ufc uff ufs uft ufu uka ukb ukc ukf ukk uku usa usb usc usf usk uss ust usu uta utb utc utf utk uts utt utu uua uuc uus uut uuu