a-a a-b a-c a-t aaa aab aac aad aao aar aat aau ab- aba abb abc abd abo abr abt abu ac- aca acb acc acd aco acr act acu ad- ada adb adc add ado adr adt adu aoa aob aoc aod aoo aor aot aou ar- ara arb arc ard aro arr art aru at- ata atb atc atd ato atr att atu au- aua aub auc aud auo aur aut b-u baa bab bac bad bao bar bat bau bba bbb bbc bbd bbo bbr bbt bbu bca bcb bcc bcd bco bcr bct bcu bda bdb bdc bdd bdo bdr bdt bdu boa bob boc bod boo bor bot bou bra brb brd bro brr brt bru bta btb btc btd bto btr btt btu bua bub buc bud buo bur but buu c-- caa cab cac cad cao car cat cau cba cbb cbc cbd cbo cbr cbt cbu cca ccb ccc ccd cco ccr cct ccu cda cdb cdc cdd cdo cdr cdt cdu co- coa cob coc cod coo cor cot cou cra crb crc crd cro crr crt cru cta ctb ctc ctd cto ctr ctt ctu cua cub cuc cud cuo cur cut cuu daa dab dac dad dao dar dat dau dba dbb dbc dbd dbo dbr dbt dbu dca dcb dcc dcd dco dcr dct dcu dda ddb ddc ddd ddo ddr ddt ddu doa dob doc dod doo dor dot dou dra drb drc drd dro drr drt dru dta dtb dtc dtd dto dtr dtt dtu dua dub duc dud duo dur dut oaa oab oac oad oao oar oat oau ob- oba obb obc obd obo obr obt obu oc- oca ocb occ ocd oco ocr oct ocu oda odb odc odd odo odr odt odu oo- ooa oob ooc ood ooo oor oot or- ora orb orc ord oro orr ort oru ot- ota otb otc otd oto otr ott otu ou- oua ouc oud ouo our out ra- raa rab rac rad rao rar rat rau rba rbb rbc rbd rbo rbr rbt rbu rca rcb rcc rcd rco rcr rct rcu rda rdb rdc rdd rdo rdr rdt rdu roa rob roc rod roo ror rot rou rra rrb rrc rrd rrr rrt rru rta rtb rtc rtd rto rtr rtt rtu rua rub ruc rud ruo rur rut ruu taa tab tac tad tao tar tat tau tba tbb tbc tbd tbo tbr tbt tbu tca tcb tcc tcd tco tcr tct tcu tda tdb tdc tdd tdo tdr tdt tdu to- toa tob toc tod too tor tot tou tra trb trc trd tro trr trt tru tta ttb ttc ttd tto ttr ttt ttu tua tub tuc tud tuo tur tut tuu ua- uaa uab uac uad uao uar uat uau uba ubb ubc ubo ubr ubt ubu uca ucb ucc ucd uco ucr uct ucu uda udb udc udd udo udr udt udu uoa uob uoc uod uoo uor uot ur- ura urb urc urd uro urr urt uru uta utb utc utd uto utr utt utu uua uuc uur uut uuu