c-- ccc ccf ccn cco ccr cfc cff cfn cfo cfr cn- cnc cnf cnn cno cnr co- coc cof con coo cor crc crf crn cro crr fcc fcf fcn fco fcr ffc fff ffn ffo ffr fnc fnf fnn fnr foc fof fon foo for frc frf frn fro frr ncc ncf ncn nco ncr nfc nff nfn nfo nfr nnc nnf nnn nno no- noc nof non noo nor nrc nrf nrn nro nrr oc- occ ocf ocn oco ocr of- ofc off ofn ofo ofr on- onc onf onn ono onr oo- ooc oof oon ooo oor or- orc orf orn oro orr rcc rcf rcn rco rcr rfc rff rfn rfo rfr rnc rnn rno rnr roc rof ron roo ror rrc rrf rrn rrr