There is an equilateral triangle ABC on the plane. Three straight lines pass through A, B and C, respectively, such that the intersections of these lines form an equilateral triangle inside ABC. On each turn, Ming chooses a two-line intersection inside ABC, and draws the straight line determined by the intersection and one of A, B and C of his choice. Find the maximum possible number of three-line intersections within ABC after 300 turns.Proposed by usjl Taiwancombinatoricsgeometry