c-- ccc ccf ccn cco cct cfc cff cfn cfo cft cn- cnc cnf cnn cno cnt co- coc cof con coo cot ctc ctf ctn cto ctt fcc fcf fcn fco fct ffc fff ffn ffo fft fnc fnf fnn fnt foc fof fon foo fot ftc ftf ftn fto ftt ncc ncf ncn nco nct nfc nff nfn nfo nft nnc nnf nnn nno nnt no- noc nof non noo not ntc ntf ntn nto ntt oc- occ ocf ocn oco oct of- ofc off ofn ofo oft on- onc onf onn ono ont oo- ooc oof oon ooo oot ot- otc otf otn oto ott tcc tcf tcn tco tct tfc tff tfn tfo tft tnc tnf tnn tno tnt to- toc tof ton too tot ttc ttf ttn tto ttt