c-- ccc cco ccr ccs co- coc coo cor cos coy crc cro crr crs cry csc cso csr css csy cyc cyo cyr cys oc- occ oco ocr ocs oo- ooc ooo oor oos or- orc oro orr ors ory os- osc oso osr oss oyo oys rcc rco rcr rcs roc roo ror ros roy rrc rrr rrs rsc rso rsr rss ry- ryc ryo ryr rys ryy scc sco scr scs soc soo sor sos soy sr- src sro srr srs sry ss- ssc sso ssr sss sy- syc syr sys ycc yco ycs ycy yoc yoo yor yos yoy yrc yro yrs ysc yso ysr yss ysy yyc yys yyy