Consider an infinitely long corridor drawn in the plane. Its floor (the bottom wall) is the segment from (0,0) to (L,0). Its two side walls are the rays that start at (0,0) and (L,0) and extend upward (in the direction of increasing y). Thus the corridor is the set of all points with 0≤x≤L and y≥0.
There are N enemies in the corridor. The i-th enemy stands at the point (xi,yi), where 0<xi<L and yi>0.
The hero stands at the point (X,0) on the floor, where 0<X<L, and throws a shield without moving. The shield flies in a straight line to a point on one side wall, bounces to a point on the other side wall, and then flies straight back to the hero. Its trajectory is therefore a triangle whose three vertices are the hero's position (X,0), a point on the left wall, and a point on the right wall. Every enemy that lies on the boundary of this triangle (on any of its three edges) is knocked out.
The hero may aim freely: the two wall vertices may be placed anywhere on the walls, at any height ≥0. Find the maximum number of enemies that can be knocked out with a single throw.
The first line contains two integers L and N — the length of the floor and the number of enemies. The second line contains one integer X — the hero's x-coordinate. Each of the next N lines contains two space-separated integers xi and yi — the coordinates of the i-th enemy.
Print one integer — the maximum number of enemies that can be knocked out with a single throw.