c-- ccc ccf ccr ccs cct ccu cfc cff cfr cfs cft cfu crc crf crr crs crt cru csc csf csr css cst csu ctc ctf ctr cts ctt ctu cuc cuf cur cus cut cuu fcc fcf fcr fcs fct fcu ffc fff ffr ffs fft ffu frc frf frr frs frt fru fsc fsf fsr fss fst fsu ftc ftf ftr fts ftt ftu fuf fur fus fut fuu rcc rcf rcr rcs rct rcu rfc rff rfr rfs rft rfu rrc rrf rrr rrs rrt rru rsc rsf rsr rss rst rsu rtc rtf rtr rts rtt rtu ruc ruf rur rus rut ruu scc scf scr scs sct scu sfc sff sfr sfs sft sfu sr- src srf srr srs srt ss- ssc ssf ssr sss sst ssu stc stf str sts stt stu suc suf sur sus sut suu tcc tcf tcr tcs tct tcu tfc tff tfr tfs tft tfu trc trf trr trs trt tru tsc tsf tsr tss tst tsu ttc ttf ttr tts ttt ttu tuc tuf tur tus tut tuu ucc ucf ucr ucs uct ucu ufc uff ufr ufs uft ufu ur- urc urf urr urs urt uru usc usf usr uss ust usu utc utf utr uts utt utu uuc uur uus uut uuu