-er a-a a-b a-c a-t aaa aab aac aad aae aak aar aat ab- aba abb abc abd abe abk abr abt ac- aca acb acc acd ace ack acr act ad- ada adb adc add ade adk adr adt aea aeb aec aed aee aek aer aet aka akb akc akd ake akk akr ar- ara arb arc ard are ark arr art at- ata atb atc atd ate atr att baa bab bac bad bae bak bar bat bba bbb bbc bbd bbe bbk bbr bbt bca bcb bcc bcd bce bck bcr bct bda bdb bdc bdd bde bdk bdr bdt be- bea beb bec bed bee bek ber bet bka bkb bkc bke bkk bkr bkt bra brb brd bre brk brr brt bta btb btc btd bte btk btr btt c-- caa cab cac cad cae cak car cat cba cbb cbc cbd cbe cbk cbr cbt cca ccb ccc ccd cce cck ccr cct cda cdb cdc cdd cde cdk cdr cdt ce- cea ceb cec ced cee cek cer cet cka ckb ckc ckd ckt cra crb crc crd cre crk crr crt cta ctb ctc ctd cte ctk ctr ctt daa dab dac dad dae dak dar dat dba dbb dbc dbd dbe dbk dbr dbt dca dcb dcc dcd dce dck dcr dct dda ddb ddc ddd dde ddk ddr ddt de- dea deb dec ded dee dek der det dka dkb dkc dke dkk dkr dkt dra drb drc drd dre drk drr drt dta dtb dtc dtd dte dtk dtr dtt eaa eab eac ead eae eak ear eat eba ebb ebc ebd ebe ebk ebr ebt ec- eca ecb ecc ecd ece eck ecr ect ed- eda edb edc edd ede edk edr edt eea eeb eec eed eee eek eer eet eka ekb ekc ekd eke ekr ekt era erb erc erd ere erk err ert eta etb etc etd ete etk etr ett k-t ka- kaa kab kac kad kae kak kar kat kba kbb kbc kbd kbe kbk kbr kca kcb kcc kcd kce kck kcr kct kda kdb kdc kde kdk kdr kdt ke- kea keb kec ked kee kek ker ket kkb kkc kke kkk kkr kkt kra krc krd krk krr krt kta ktb ktc kte ktk ktr ktt ra- raa rab rac rad rae rak rar rat rba rbb rbc rbd rbe rbk rbr rbt rca rcb rcc rcd rce rcr rct rda rdb rdc rdd rde rdr rdt re- rea reb rec red ree rek rer ret rkb rkc rke rkk rkt rra rrb rrc rrd rrk rrr rrt rta rtb rtc rtd rte rtk rtr rtt taa tab tac tad tae tak tar tat tba tbb tbc tbd tbe tbk tbr tbt tca tcb tcc tcd tce tck tcr tct tda tdb tdc tdd tde tdk tdr tdt te- tea teb tec ted tee tek ter tet tka tkb tkc tke tkk tkr tkt tra trb trc trd tre trk trr trt tta ttb ttc ttd tte ttk ttr ttt