c-- ccc ccf cco ccr ccs ccu cfc cff cfo cfr cfs cfu co- coc cof coo cor cos cou crc crf cro crr crs cru csc csf cso csr css csu cuc cuf cuo cur cus cuu fcc fcf fco fcr fcs fcu ffc fff ffo ffr ffs ffu foc fof foo for fos fou frc frf fro frr frs fru fsc fsf fso fsr fss fsu fuf fuo fur fus fuu oc- occ ocf oco ocr ocs ocu of- ofc off ofo ofr ofs ofu oo- ooc oof ooo oor oos or- orc orf oro orr ors oru os- osc osf oso osr oss osu ou- ouc ouf ouo our ous rcc rcf rco rcr rcs rcu rfc rff rfo rfr rfs rfu roc rof roo ror ros rou rrc rrf rrr rrs rru rsc rsf rso rsr rss rsu ruc ruf ruo rur rus ruu scc scf sco scr scs scu sfc sff sfo sfr sfs sfu soc sof soo sor sos sou sr- src srf sro srr srs ss- ssc ssf sso ssr sss ssu suc suf suo sur sus suu ucc ucf uco ucr ucs ucu ufc uff ufo ufr ufs ufu uoc uoo uor uos ur- urc urf uro urr urs uru usc usf uso usr uss usu uuc uur uus uuu