a-a a-b aaa aab aad aar aay ab- aba abb abd abr aby ad- ada adb add adr ady ar- ara arb ard arr ary ay- aya ayd ayr baa bab bad bar bay bba bbb bbd bbr bby bda bdb bdd bdr bdy bra brb brd brr bry by- bya byd byr daa dab dad dar day dba dbb dbd dbr dby dda ddb ddd ddr ddy dra drb drd drr dry dy- dya dyb dyd dyr dyy ra- raa rab rad rar ray rba rbb rbd rbr rda rdb rdd rdr rdy rra rrb rrd rrr ry- rya ryd ryr ryy yaa yab yad yar yay ybr yby yda ydy yra yyb yyy