a-a a-b a-c aaa aab aac aak aao aar aaw ab- aba abb abc abk abo abr abw ac- aca acb acc ack aco acr acw aka akb akc akk ako akr akw aoa aob aoc aok aoo aor aow ar- ara arb arc ark aro arr arw aw- awa awb awc awk awo awr aww baa bab bac bak bao bar baw bba bbb bbc bbk bbo bbr bbw bca bcb bcc bck bco bcr bka bkb bkc bkk bko bkr bkw boa bob boc bok boo bor bow bra brb brk bro brr brw bwa bwb bwc bwk bwo bwr c-- caa cab cac cak cao car caw cba cbb cbc cbk cbo cbr cbw cca ccb ccc cck cco ccr ccw cka ckb ckc cko ckw co- coa cob coc cok coo cor cow cra crb crc crk cro crr crw cw- cwa cwb cwc cwk cwo cwr ka- kaa kab kac kak kao kar kaw kba kbb kbc kbk kbo kbr kbw kca kcb kcc kck kcr kkb kkc kkk kkr koa kob koc kok koo kor kow kra krc krk kro krr krw kw- kwa kwc kwk kwo kww oaa oab oac oak oao oar oaw ob- oba obb obc obk obo obr obw oc- oca ocb occ ock oco ocr ocw oka okb okc okk oko okr okw oo- ooa oob ooc ook ooo oor oow or- ora orb orc ork oro orr owa owb owc owk owo oww ra- raa rab rac rak rao rar raw rba rbb rbc rbk rbo rbr rbw rca rcb rcc rco rcr rcw rkb rkc rkk rko roa rob roc rok roo ror row rra rrb rrc rrk rrr rwa rwb rwc rwr waa wab wac wak wao war waw wba wbb wbc wbo wbr wbw wca wcb wcc wck wco wcr wcw wka wkb wkc wko wkr wkw woa wob woc wok woo wor wow wr- wra wrc wrk wro wrr wrw wwa wwc wwo www