a-a a-b a-c aaa aab aac aad aar aau aay ab- aba abb abc abd abr abu aby ac- aca acb acc acd acr acu acy ad- ada adb adc add adr adu ady ar- ara arb arc ard arr aru ary au- aua aub auc aud aur ay- aya ayc ayd ayr ayu b-u baa bab bac bad bar bau bay bba bbb bbc bbd bbr bbu bby bca bcb bcc bcd bcr bcu bcy bda bdb bdc bdd bdr bdu bdy bra brb brd brr bru bry bua bub buc bud bur buu buy by- bya byc byd byr byu c-- caa cab cac cad car cau cay cba cbb cbc cbd cbr cbu cby cca ccb ccc ccd ccr ccu cda cdb cdc cdd cdr cdu cdy cra crb crc crd crr cru cry cua cub cuc cud cur cuu cuy cya cyb cyc cyd cyr daa dab dac dad dar dau day dba dbb dbc dbd dbr dbu dby dca dcb dcc dcd dcr dcu dda ddb ddc ddd ddr ddu ddy dra drb drc drd drr dru dry dua dub duc dud dur duy dy- dya dyb dyc dyd dyr dyu dyy ra- raa rab rac rad rar rau ray rba rbb rbc rbd rbr rbu rca rcb rcc rcd rcr rcu rda rdb rdc rdd rdr rdu rdy rra rrb rrc rrd rrr rru rua rub ruc rud rur ruu ruy ry- rya ryc ryd ryr ryu ryy ua- uaa uab uac uad uar uau uay uba ubb ubc ubr ubu uby uca ucb ucc ucd ucr ucu uda udb udc udd udr udu ur- ura urb urc urd urr uru ury uua uuc uur uuu uyc uyu yaa yab yac yad yar yau yay ybc ybr yby yca ycc ycd ycu ycy yda ydy yra yrc yru yua yud yur yuu yuy yyb yyc yyu yyy