k-t kkk kkr kks kkt kok koo kor kos kot krk kro krr krs krt ksk kso ksr kss kst ktk kto ktr kts ktt okk oko okr oks oo- ook ooo oor oos oot or- ork oro orr ors ort os- osk oso osr oss ost ot- otk oto otr ots ott rkk rko rks rkt rok roo ror ros rot rrk rrr rrs rrt rsk rso rsr rss rst rtk rto rtr rts rtt sk- skk sko skr sks skt sok soo sor sos sot sr- srk sro srr srs srt ss- ssk sso ssr sss sst stk sto str sts stt tkk tko tkr tks tkt to- tok too tor tos tot trk tro trr trs trt tsk tso tsr tss tst ttk tto ttr tts ttt