a-a a-b a-c aaa aab aac aak aaw aay ab- aba abb abc abk abw aby ac- aca acb acc ack acw acy aka akb akc akk akw aw- awa awb awc awk aww awy ay- aya ayc ayk ayw baa bab bac bak baw bay bba bbb bbc bbk bbw bby bca bcb bcc bck bcy bka bkb bkc bkk bkw bwa bwb bwc bwk bwy by- bya byc byk c-- caa cab cac cak caw cay cba cbb cbc cbk cbw cby cca ccb ccc cck ccw cka ckb ckc ckw cky cw- cwa cwb cwc cwk cya cyb cyc cyk cyw ka- kaa kab kac kak kaw kay kba kbb kbc kbk kbw kca kcb kcc kck kkb kkc kkk kky kw- kwa kwc kwk kww kya kyc kyw waa wab wac wak waw way wba wbb wbc wbw wca wcb wcc wck wcw wka wkb wkc wkw wky wwa wwc www wy- wya wyc wyk yaa yab yac yak yaw yay ybc yby yca ycc ycw ycy yka ykk ywc yyb yyc yyy