B'You are given n distinct points p_1, p_2, ldots, p_n on the plane and a positive integer R . Find the number of pairs of indices (i, j) such that 1 <= i < j <= n , and for every possible k ( 1 <= k <= n ) the distance from the point p_k to the segment between points p_i and p_j is at most R . The first line contains two integers n , R ( 1 <= n <= 3000 , 1 <= R <= 10^5 ) -- the number of points and the maximum distance between a point and a segment. Each of the next n lines contains two integers x_i , y_i ( -10^5 <= x_i, y_i <= 10^5 ) that define the i -th point p_i=(x_i, y_i) . All points are distinct. It is guaranteed that the answer does not change if the parameter R is changed by at most 10^{-2} . Print the number of suitable pairs (i, j) . In the first example, the only pair of points (-3, 0) , (3, 0) is suitable. The distance to the segment between these points from the points (0, 1) and (0, -1) is equal to 1 , which is less than R=2 . In the second example, all possible pairs of points are eligible. '...