a-a a-b a-c a-z aaa aab aac aak aao aaw aaz ab- aba abb abc abk abo abw abz ac- aca acb acc ack aco acw acz aka akb akc akk ako akw aoa aob aoc aok aoo aow aw- awa awb awc awk awo aww az- aza azb azo azw azz baa bab bac bak bao baw baz bba bbb bbc bbk bbo bbw bca bcb bcc bck bco bcz bka bkb bkc bkk bko bkw boa bob boc bok boo bow boz bwa bwb bwc bwk bwo bza bzo bzz c-- caa cab cac cak cao caw caz cba cbb cbc cbk cbo cbw cbz cca ccb ccc cck cco ccw ccz cka ckb ckc cko ckw co- coa cob coc cok coo cow coz cw- cwa cwb cwc cwk cwo cz- czc czk czo czw k-z ka- kaa kab kac kak kao kaw kaz kba kbb kbc kbk kbo kbw kbz kca kcb kcc kck kkb kkc kkk koa kob koc kok koo kow koz kw- kwa kwc kwk kwo kww kzo kzw oaa oab oac oak oao oaw ob- oba obb obc obk obo obw oc- oca ocb occ ock oco ocw ocz oka okb okc okk oko okw oo- ooa oob ooc ook ooo oow owa owb owc owk owo oww oza ozo ozw ozz waa wab wac wak wao waw waz wba wbb wbc wbo wbw wbz wca wcb wcc wck wco wcw wka wkb wkc wko wkw woa wob woc wok woo wow woz wwa wwc wwo www wzc zaa zab zac zak zao zaz zbb zbc zbw zco zka zo- zoa zob zoc zok zoo zow zzz