Although bobo is truly smart, he just like you to find a simple polygon for him. The polygon you are going to find should satisfy the following conditions.
First line of the input contains two integers l and s (4≤l≤109,1≤s≤109).
The first line contains an integer n, which denotes the number of vertices of the polygon you have found (4≤n≤1000).
Each of the following n lines contains 2 integers x_i,y_i, which denote the coordinates of points (in clockwise or counter-clockwise order) (0≤x_i,y_i≤109).
Any appropriate solution will get accepted.
If no such polygon can be found, simply print "-1".