The are N points on the plane (N is even). No three points lie on the same straight line. Your task is to select two points in such a way, that straight line they belong to divides the set of points into two equal-sized parts.

First line contains one integer N (4 ≤ N ≤ 10000). Each of next N lines contains pair of integers x_i, y_i (−10⁶ ≤ x_i, y_i ≤ 10⁶), the coordinates of i-th point.

Print the numbers of selected points.