-al -er a-a a-b a-c a-t aaa aab aac aae aak aal aar aat ab- aba abb abc abe abk abl abr abt ac- aca acb acc ace ack acl acr act aea aeb aec aee aek ael aer aet aka akb akc ake akk akl akr al- ala alb alc ale alk all alr alt ar- ara arb arc are ark arl arr art at- ata atb atc ate atl atr att baa bab bac bae bak bal bar bat bba bbb bbc bbe bbk bbl bbr bbt bca bcb bcc bce bck bcl bcr bct be- bea beb bec bee bek bel ber bet bka bkb bkc bke bkk bkl bkr bkt bla blb blc ble blk bll blr blt bra brb bre brk brl brr brt bta btb btc bte btk btl btr btt c-- caa cab cac cae cak cal car cat cba cbb cbc cbe cbk cbl cbr cbt cca ccb ccc cce cck ccl ccr cct ce- cea ceb cec cee cek cel cer cet cka ckb ckc ckt cl- cla clb clc cle clk cll clr clt cra crb crc cre crk crl crr crt cta ctb ctc cte ctk ctl ctr ctt eaa eab eac eae eak eal ear eat eba ebb ebc ebe ebk ebl ebr ebt ec- eca ecb ecc ece eck ecl ecr ect eea eeb eec eee eek eel eer eet eka ekb ekc eke ekl ekr ekt ela elb elc ele elk ell elr elt era erb erc ere erk erl err ert eta etb etc ete etk etl etr ett k-t ka- kaa kab kac kae kak kal kar kat kba kbb kbc kbe kbk kbl kbr kca kcb kcc kce kck kcl kcr kct ke- kea keb kec kee kek kel ker ket kkb kkc kke kkk kkl kkr kkt kl- kla klb klc klr klt kra krc krk krl krr krt kta ktb ktc kte ktk ktl ktr ktt la- laa lab lac lae lak lal lar lat lba lbb lbc lbe lbk lbl lbr lbt lca lcb lcc lce lck lcl lcr lct lea leb lec lee lek lel ler let lka lkb lkl lkr lkt lla llb llc lle llk lll llr llt lra lrb lrc lrk lrr lrt lta ltb ltc lte ltk ltl ltr ltt ra- raa rab rac rae rak ral rar rat rba rbb rbc rbe rbk rbl rbr rbt rca rcb rcc rce rcl rcr rct re- rea reb rec ree rek rel rer ret rkb rkc rke rkk rkt rla rlc rle rll rlr rlt rra rrb rrc rrk rrl rrr rrt rta rtb rtc rte rtk rtl rtr rtt taa tab tac tae tak tal tar tat tba tbb tbc tbe tbk tbl tbr tbt tca tcb tcc tce tck tcl tcr tct te- tea teb tec tee tek tel ter tet tka tkb tkc tke tkk tkl tkr tkt tla tlc tle tlk tll tlr tlt tra trb trc tre trk trl trr trt tta ttb ttc tte ttk ttl ttr ttt