Sereja and Squares

Description:

Input:

The first line contains integer n (1 ≤ n ≤ 10⁵). Each of the next n lines contains two integers x_i, y_i (0 ≤ x_i, y_i ≤ 10⁵), the integers represent the coordinates of the i-th point. It is guaranteed that all the given points are distinct.

Output:

In a single line print the required number of squares.

Sample Input:

5
0 0
0 2
2 0
2 2
1 1

Sample Output:

1

Sample Input:

9
0 0
1 1
2 2
0 1
1 0
0 2
2 0
1 2
2 1

Sample Output:

5