b-u bbb bbd bbi bbr bbt bbu bdb bdd bdi bdr bdt bdu bi- bib bid bii bir bit biu brb brd bri brr brt bru btb btd bti btr btt btu bub bud bui bur but buu dbb dbd dbi dbr dbt dbu ddb ddd ddi ddr ddt ddu di- dib did dii dir dit diu drb drd dri drr drt dru dtb dtd dti dtr dtt dtu dub dud dui dur dut i-d ibb ibd ibi ibr ibt ibu idb idd idi idr idt idu iib iid iii iir iit iiu ir- irb ird iri irr irt iru itb itd iti itt itu iu- iub iud iui iur iut rbb rbd rbi rbr rbt rbu rdb rdd rdi rdr rdt rdu rib rid rii rir rit rrb rrd rri rrr rrt rru rtb rtd rti rtr rtt rtu rub rud rui rur rut ruu tbb tbd tbi tbr tbt tbu tdb tdd tdi tdr tdt tdu tib tid tii tir tit tiu trb trd tri trr trt tru ttb ttd tti ttr ttt ttu tub tud tui tur tut tuu ubb ubi ubr ubt ubu udb udd udi udr udt udu uib uid uii uir uit uiu ur- urb urd uri urr urt uru utb utd uti utr utt utu uur uut uuu