-up b-p b-u bbb bbp bbr bbs bbt bbu bpb bpp bpr bps bpt bpu brb brp brr brs brt bru bsb bsp bsr bss bst bsu btb btp btr bts btt btu bub bup bur bus but buu p-p pbb pbp pbr pbs pbt pbu ppb ppp ppr pps ppt ppu prb prp prr prs prt pru ps- psb psp psr pss pst psu pt- ptb ptp ptr pts ptt ptu pub pup pur pus put puu rbb rbp rbr rbs rbt rbu rpb rpp rpr rps rpt rpu rrb rrp rrr rrs rrt rru rsb rsp rsr rss rst rsu rtb rtp rtr rts rtt rtu rub rup rur rus rut ruu sbb sbp sbr sbs sbt sbu spb spp spr sps spt spu sr- srb srp srr srs srt ss- ssb ssp ssr sss sst ssu stb stp str sts stt stu sub sup sur sus sut suu tbb tbp tbr tbs tbt tbu tpb tpp tpr tps tpt tpu trb trp trr trs trt tru tsb tsp tsr tss tst tsu ttb ttp ttr tts ttt ttu tub tup tur tus tut tuu ubb ubp ubr ubs ubt ubu up- upb upp upr ups upt upu ur- urb urp urr urs urt uru usb usp usr uss ust usu utb utp utr uts utt utu uur uus uut uuu