The are N points on the plane (N is even). No three points belong to the same strait line.
Your task is to select two points in such a way, that strait line they belong to divides the set of points into two equal-sized parts.
First line contains one integer N (2 ≤ N ≤ 10000).
Each of next N lines contains pair of integers xi, yi (−109 ≤ xi, yi ≤ 109), the coordinates of
Print the numbers of selected points.
Problem Author: Pavel Atnashev
Problem Source: USU Internal Contest, March 2002