bbb bbg bbi bbr bbt bgb bgg bgi bgr bgt bi- bib big bii bir bit brb brg bri brr brt btb btg bti btr btt gbg gbi gbr gbt ggb ggg ggi ggr ggt gib gig gii gir git grb grg gri grr grt gtb gtg gti gtr gtt ibb ibg ibi ibr ibt igb igg igi igr igt iib iii iir iit ir- irb irg iri irr irt itb itg iti itt rbb rbg rbi rbr rbt rgb rgg rgi rgr rgt rib rig rii rir rit rrb rrg rri rrr rrt rtb rtg rti rtr rtt tbb tbg tbi tbr tbt tgb tgg tgi tgr tgt tib tig tii tir tit trb trg tri trr trt ttb ttg tti ttr ttt