bbb bbd bbi bbr bbt bdb bdd bdi bdr bdt bi- bib bid bii bir bit brb brd bri brr brt btb btd bti btr btt dbb dbd dbi dbr dbt ddb ddd ddi ddr ddt di- dib did dii dir dit drb drd dri drr drt dtb dtd dti dtr dtt i-d ibb ibd ibi ibr ibt idb idd idi idr idt iib iid iii iir iit ir- irb ird iri irr irt itb itd iti itt rbb rbd rbi rbr rbt rdb rdd rdi rdr rdt rib rid rii rir rit rrb rrd rri rrr rrt rtb rtd rti rtr rtt tbb tbd tbi tbr tbt tdb tdd tdi tdr tdt tib tid tii tir tit trb trd tri trr trt ttb ttd tti ttr ttt