m-r mmm mmr mms mmt mmu mrm mrr mrs mrt mru msm msr mss mst msu mtm mtr mts mtt mtu mum mur mus mut muu rmm rmr rms rmt rrm rrr rrs rrt rru rsm rsr rss rst rsu rtm rtr rts rtt rtu rum rur rus rut ruu smm smr sms smt smu sr- srm srr srs srt ss- ssm ssr sss sst ssu stm str sts stt stu sum sur sus sut suu tmm tmr tms tmt tmu trm trr trs trt tru tsm tsr tss tst tsu ttm ttr tts ttt ttu tum tur tus tut tuu um- umm umr ums umt umu ur- urm urr urs urt uru usm usr uss ust usu utm utr uts utt utu uum uur uus uut uuu