c-- ccc cco ccr ccs cct ccu co- coc coo cor cos cot cou crc cro crr crs crt cru csc cso csr css cst csu ctc cto ctr cts ctt ctu cuc cuo cur cus cut cuu oc- occ oco ocr ocs oct ocu oo- ooc ooo oor oos oot or- orc oro orr ors ort oru os- osc oso osr oss ost osu ot- otc oto otr ots ott otu ou- ouc ouo our ous out rcc rco rcr rcs rct rcu roc roo ror ros rot rou rrc rrr rrs rrt rru rsc rso rsr rss rst rsu rtc rto rtr rts rtt rtu ruc ruo rur rus rut ruu scc sco scr scs sct scu soc soo sor sos sot sou sr- src sro srr srs srt ss- ssc sso ssr sss sst ssu stc sto str sts stt stu suc suo sur sus sut suu tcc tco tcr tcs tct tcu to- toc too tor tos tot tou trc tro trr trs trt tru tsc tso tsr tss tst tsu ttc tto ttr tts ttt ttu tuc tuo tur tus tut tuu ucc uco ucr ucs uct ucu uoc uoo uor uos uot ur- urc uro urr urs urt uru usc uso usr uss ust usu utc uto utr uts utt utu uuc uur uus uut uuu