a-a a-b a-c a-t aaa aab aac aad aaf aak aar aat ab- aba abb abc abd abf abk abr abt ac- aca acb acc acd acf ack acr act ad- ada adb adc add adf adk adr adt af- afa afb afc afd aff afk afr aft aka akb akc akd akk akr ar- ara arb arc ard arf ark arr art at- ata atb atc atd atf atr att baa bab bac bad baf bak bar bat bba bbb bbc bbd bbf bbk bbr bbt bca bcb bcc bcd bcf bck bcr bct bda bdb bdc bdd bdf bdk bdr bdt bfa bfb bfc bfd bff bfr bft bka bkb bkc bkf bkk bkr bkt bra brb brd brf brk brr brt bta btb btc btd btf btk btr btt c-- caa cab cac cad caf cak car cat cba cbb cbc cbd cbf cbk cbr cbt cca ccb ccc ccd ccf cck ccr cct cda cdb cdc cdd cdf cdk cdr cdt cfa cfb cfc cfd cff cfk cfr cft cka ckb ckc ckd ckt cra crb crc crd crf crk crr crt cta ctb ctc ctd ctf ctk ctr ctt daa dab dac dad daf dak dar dat dba dbb dbc dbd dbf dbk dbr dbt dca dcb dcc dcd dcf dck dcr dct dda ddb ddc ddd ddf ddk ddr ddt dfa dfb dfc dfd dff dfk dfr dft dka dkb dkc dkk dkr dkt dra drb drc drd drk drr drt dta dtb dtc dtd dtf dtk dtr dtt faa fab fac fad faf fak far fat fba fbb fbc fbd fbf fbk fbr fbt fca fcb fcc fcd fcf fck fcr fct fda fdb fdc fdd fdf fdk fdr fdt ffa ffc ffd fff ffk ffr fft fka fkb fkc fkf fkk fkt fra frb frc frd frf frk frr frt fta ftb ftc ftd ftf ftk ftr ftt k-t ka- kaa kab kac kad kaf kak kar kat kba kbb kbc kbd kbf kbk kbr kca kcb kcc kcd kck kcr kct kda kdb kdc kdf kdk kdr kdt kfa kfc kfd kff kkb kkc kkk kkr kkt kra krc krd krf krk krr krt kta ktb ktc ktf ktk ktr ktt ra- raa rab rac rad raf rak rar rat rba rbb rbc rbd rbf rbk rbr rbt rca rcb rcc rcd rcf rcr rct rda rdb rdc rdd rdf rdr rdt rfa rfb rfc rfd rff rfk rfr rft rkb rkc rkf rkk rkt rra rrb rrc rrd rrf rrk rrr rrt rta rtb rtc rtd rtf rtk rtr rtt taa tab tac tad taf tak tar tat tba tbb tbc tbd tbf tbk tbr tbt tca tcb tcc tcd tcf tck tcr tct tda tdb tdc tdd tdf tdk tdr tdt tfa tfb tfc tfd tff tfk tfr tft tka tkb tkc tkk tkr tkt tra trb trc trd trf trk trr trt tta ttb ttc ttd ttf ttk ttr ttt