c-- ccc ccf cco ccr cfc cff cfo cfr co- coc cof coo cor coy crc crf cro crr cry cyc cyf cyo cyr fcc fcf fco fcr fcy ffc fff ffo ffr ffy foc fof foo for foy frc frf fro frr fry fy- fyc fyo oc- occ ocf oco ocr of- ofc off ofo ofr oo- ooc oof ooo oor or- orc orf oro orr ory oyo rcc rcf rco rcr rfc rff rfo rfr roc rof roo ror roy rrc rrf rrr ry- ryc ryf ryo ryr ryy ycc ycf yco ycy yfc yff yfr yoc yof yoo yor yoy yrc yrf yro yyc yyf yyy