D. Sereja and Squares
time limit per test
2 seconds
memory limit per test
512 megabytes
input
stdin
output
stdout

Sereja has painted n distinct points on the plane. The coordinates of each point are integers. Now he is wondering: how many squares are there with sides parallel to the coordinate axes and with points painted in all its four vertexes? Help him, calculate this number.

Input

The first line contains integer n (1 ≤ n ≤ 105). Each of the next n lines contains two integers xi, yi (0 ≤ xi, yi ≤ 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.

Examples
Input
5
0 0
0 2
2 0
2 2
1 1
Output
1
Input
9
0 0
1 1
2 2
0 1
1 0
0 2
2 0
1 2
2 1
Output
5