a-a aaa aaf aak aan aao aar aax af- afa aff afk afn afo afr afx aka akk akn ako akr an- ana anf ank ann ano anr anx aoa aof aok aon aoo aor aox ar- ara arf ark arn aro arr arx ax- axa axk axn axo axr axx faa faf fak fan fao far fax ffa fff ffk ffn ffo ffr ffx fka fkf fkk fna fnf fnk fnn fnr fnx foa fof fok fon foo for fox fra frf frk frn fro frr fxr fxx ka- kaa kaf kak kan kao kar kax kfa kff kfo kfx kkk kkn kkr kn- kna knf knk knn kno knr knx koa kof kok kon koo kor kra krf krk krn kro krr kxo naa naf nak nan nao nar nax nfa nff nfk nfn nfo nfr nka nkf nkk nkn nko nkr nna nnf nnk nnn nno no- noa nof nok non noo nor nox nra nrf nrk nrn nro nrr nrx oaa oaf oak oan oao oar oax of- ofa off ofn ofo ofr ofx oka okk oko okr on- ona onf onk onn ono onr onx oo- ooa oof ook oon ooo oor oox or- ora orf ork orn oro orr orx ox- oxa oxf oxn oxo oxx ra- raa raf rak ran rao rar rax rfa rff rfk rfn rfo rfr rkf rkk rko rna rnn rno rnr roa rof rok ron roo ror rox rra rrf rrk rrn rrr rxr xaa xaf xak xan xar xfa xfn xfx xna xnk xno xoa xof xok xon xoo xor xox xrf xrx xxo xxx