Alice Bob tree undirecte acyclic connect graph there ai chocolate waiting pick ith vertex tree first choose different vertex start position Alice choose chocolate contain themThen alternate move select vertex time collect chocolate node to thing interesting decide select vertex heshe select vertex adjacent hisher previous turn vertex choose moveif moment able select node satisfy rule heshe skip turn let person pick chocolate long heshe this go pick chocolate furtherDue greed chocolate want collect chocolate possible however friend care total number chocolate obtain what maximum total number chocolate pick