Luba surf internet she currently n open tabs browser index 1 n leave right the mouse cursor currently locate posth tab Luba need use tab indice l r inclusive study want close tab do not belong segment fast possibleeach second Luba try move cursor leave right cursor currently tab tab maxi1a tab mini1b try close tab leave right cursor cursor currently tab close tab index segment ai1 segment i1b in aforementioned expression b denote minimum maximum index unclosed tab respectively for example 7 tab initially tab 1 2 7 close a3 b6what minimum number second Luba spend order leave tabs initial indice l r inclusive open