-er a-a a-b a-c a-t aaa aab aac aae aak aar aat aau ab- aba abb abc abe abk abr abt abu ac- aca acb acc ace ack acr act acu aea aeb aec aee aek aer aet aeu aka akb akc ake akk akr aku ar- ara arb arc are ark arr art aru at- ata atb atc ate atr att atu au- aua aub auc aue auk aur aut b-u baa bab bac bae bak bar bat bau bba bbb bbc bbe bbk bbr bbt bbu bca bcb bcc bce bck bcr bct bcu be- bea beb bec bee bek ber bet beu bka bkb bkc bke bkk bkr bkt bra brb bre brk brr brt bru bta btb btc bte btk btr btt btu bua bub buc bue buk bur but buu c-- caa cab cac cae cak car cat cau cba cbb cbc cbe cbk cbr cbt cbu cca ccb ccc cce cck ccr cct ccu ce- cea ceb cec cee cek cer cet ceu cka ckb ckc ckt cra crb crc cre crk crr crt cru cta ctb ctc cte ctk ctr ctt ctu cua cub cuc cue cuk cur cut cuu eaa eab eac eae eak ear eat eau eba ebb ebc ebe ebk ebr ebt ebu ec- eca ecb ecc ece eck ecr ect ecu eea eeb eec eee eek eer eet eka ekb ekc eke ekr ekt eku era erb erc ere erk err ert eru eta etb etc ete etk etr ett etu eu- eua eub euc eue eur eut k-t ka- kaa kab kac kae kak kar kat kau kba kbb kbc kbe kbk kbr kbu kca kcb kcc kce kck kcr kct kcu ke- kea keb kec kee kek ker ket kkb kkc kke kkk kkr kkt kku kra krc krk krr krt kru kta ktb ktc kte ktk ktr ktt ktu kub kuc kue kuk kur kut kuu ra- raa rab rac rae rak rar rat rau rba rbb rbc rbe rbk rbr rbt rbu rca rcb rcc rce rcr rct rcu re- rea reb rec ree rek rer ret reu rkb rkc rke rkk rkt rku rra rrb rrc rrk rrr rrt rru rta rtb rtc rte rtk rtr rtt rtu rua rub ruc rue ruk rur rut ruu taa tab tac tae tak tar tat tau tba tbb tbc tbe tbk tbr tbt tbu tca tcb tcc tce tck tcr tct tcu te- tea teb tec tee tek ter tet teu tka tkb tkc tke tkk tkr tkt tra trb trc tre trk trr trt tru tta ttb ttc tte ttk ttr ttt ttu tua tub tuc tue tuk tur tut tuu ua- uaa uab uac uae uak uar uat uau uba ubb ubc ube ubk ubr ubt ubu uca ucb ucc uce uck ucr uct ucu uea ueb uec uee uer uet uka ukb ukc uke ukk ukr uku ur- ura urb urc ure urk urr urt uru uta utb utc ute utk utr utt utu uua uuc uue uur uut uuu