c-- ccc ccf ccn cco ccs cct cfc cff cfn cfo cfs cft cn- cnc cnf cnn cno cns cnt co- coc cof con coo cos cot csc csf csn cso css cst ctc ctf ctn cto cts ctt fcc fcf fcn fco fcs fct ffc fff ffn ffo ffs fft fnc fnf fnn fns fnt foc fof fon foo fos fot fsc fsf fsn fso fss fst ftc ftf ftn fto fts ftt ncc ncf ncn nco ncs nct nfc nff nfn nfo nfs nft nnc nnf nnn nno nns nnt no- noc nof non noo nos not nsc nsf nsn nso nss nst ntc ntf ntn nto nts ntt oc- occ ocf ocn oco ocs oct of- ofc off ofn ofo ofs oft on- onc onf onn ono ons ont oo- ooc oof oon ooo oos oot os- osc osf osn oso oss ost ot- otc otf otn oto ots ott scc scf scn sco scs sct sfc sff sfn sfo sfs sft snc snf snn sno sns snt soc sof son soo sos sot ss- ssc ssf ssn sso sss sst stc stf stn sto sts stt tcc tcf tcn tco tcs tct tfc tff tfn tfo tfs tft tnc tnf tnn tno tns tnt to- toc tof ton too tos tot tsc tsf tsn tso tss tst ttc ttf ttn tto tts ttt