c-- ccc ccd cco ccr ccs cdc cdd cdo cdr cds cdy co- coc cod coo cor cos coy crc crd cro crr crs cry csc csd cso csr css csy cyc cyd cyo cyr cys dcc dcd dco dcr dcs ddc ddd ddo ddr dds ddy doc dod doo dor dos doy drc drd dro drr drs dry dsc dsd dso dsr dss dsy dy- dyc dyd dyo dyr dys dyy oc- occ ocd oco ocr ocs odc odd odo odr ods oo- ooc ood ooo oor oos or- orc ord oro orr ors ory os- osc osd oso osr oss oyd oyo oys rcc rcd rco rcr rcs rdc rdd rdo rdr rds rdy roc rod roo ror ros roy rrc rrd rrr rrs rsc rsd rso rsr rss ry- ryc ryd ryo ryr rys ryy scc scd sco scr scs sdc sdd sdo sdr sds sdy soc sod soo sor sos soy sr- src srd sro srr srs sry ss- ssc ssd sso ssr sss sy- syc syd syr sys ycc ycd yco ycs ycy ydo yds ydy yoc yod yoo yor yos yoy yrc yro yrs ysc yso ysr yss ysy yyc yys yyy