a-a a-b a-t aaa aab aag aao aar aat aay ab- aba abb abg abo abr abt aby ag- aga agb agg ago agr agt agy aoa aob aog aoo aor aot ar- ara arb arg aro arr art ary at- ata atb atg ato atr att ay- aya ayo ayr ayt baa bab bag bao bar bat bay bba bbb bbg bbo bbr bbt bby bga bgb bgg bgo bgr bgt boa bob bog boo bor bot boy bra brb brg bro brr brt bry bta btb btg bto btr btt bty by- bya byg byo byr byt gaa gab gag gao gar gat gay gba gbg gbo gbr gbt gby gga ggb ggg ggo ggr ggt goa gob gog goo gor got goy gra grb grg gro grr grt gry gta gtb gtg gto gtr gtt gty gy- gya gyb gyo gyr oaa oab oag oao oar oat ob- oba obb obg obo obr obt oby oga ogg ogo ogt ogy oo- ooa oob oog ooo oor oot or- ora orb org oro orr ort ory ot- ota otb otg oto otr ott oya oyo ra- raa rab rag rao rar rat ray rba rbb rbg rbo rbr rbt rga rgb rgg rgo rgr rgt roa rob rog roo ror rot roy rra rrb rrg rrr rrt rta rtb rtg rto rtr rtt rty ry- rya ryg ryo ryr ryy taa tab tag tao tar tat tay tba tbb tbg tbo tbr tbt tga tgb tgg tgo tgr tgt tgy to- toa tob tog too tor tot toy tra trb trg tro trr trt try tta ttb ttg tto ttr ttt tty tya tyg tyo tyr tyt yaa yab yag yao yar yat yay ybg ybr yby yga ygo yob yog yoo yor yot yoy yra yrg yro yrt yta yto ytr ytt yyb yyg yyt yyy