c-- ccc cco ccr ccs ccx co- coc coo cor cos cox coy crc cro crr crs crx cry csc cso csr css csx csy cxc cxo cxr cxs cxx cyc cyo cyr cys oc- occ oco ocr ocs ocx oo- ooc ooo oor oos oox or- orc oro orr ors orx ory os- osc oso osr oss osx ox- oxc oxo oxx oxy oyo oys rcc rco rcr rcs rcx roc roo ror ros rox roy rrc rrr rrs rsc rso rsr rss rsx rxr rxs ry- ryc ryo ryr rys ryy scc sco scr scs scx soc soo sor sos sox soy sr- src sro srr srs srx sry ss- ssc sso ssr sss ssx sxc sxs sy- syc syr sys syx xcr xcx xoc xoo xor xos xox xrc xrx xry xsc xss xxo xxx xxy xyr xyy ycc yco ycs ycy yoc yoo yor yos yox yoy yrc yro yrs ysc yso ysr yss ysy yxy yyc yys yyy