a-a a-c aaa aac aaf aan aao aax aay ac- aca acc acf acn aco acx acy af- afa afc aff afn afo afx afy an- ana anc anf ann ano anx any aoa aoc aof aon aoo aox ax- axa axn axo axx ay- aya ayc ayf ayn ayo ayx c-- caa cac caf can cao cax cay cca ccc ccf ccn cco ccx cfa cfc cff cfn cfo cfx cn- cna cnc cnf cnn cno cnx cny co- coa coc cof con coo cox coy cxc cxf cxo cxx cya cyc cyf cyn cyo faa fac faf fan fao fax fay fca fcc fcf fcn fco fcx fcy ffa ffc fff ffn ffo ffx ffy fna fnc fnf fnn fnx foa foc fof fon foo fox foy fxx fy- fya fyc fyn fyo naa nac naf nan nao nax nay nca ncc ncf ncn nco ncx nfa nfc nff nfn nfo nna nnc nnf nnn nno no- noa noc nof non noo nox noy nxc nya nyc nyf nyn nyo nyx nyy oaa oac oaf oan oao oax oc- oca occ ocf ocn oco ocx of- ofa ofc off ofn ofo ofx on- ona onc onf onn ono onx ony oo- ooa ooc oof oon ooo oox ox- oxa oxc oxf oxn oxo oxx oxy oya oyo xaa xac xaf xan xcf xcx xfa xfn xfx xna xnc xno xoa xoc xof xon xoo xox xxo xxx xxy xyy yaa yac yaf yan yao yax yay yca ycc ycf yco ycy yfa yfc yff yna ynn yny yoc yof yon yoo yox yoy yxa yxy yyc yyf yyy