CF425D.Sereja and Squares

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.

Sereja 在平面上画了 $n$ 个互不相同的点，每个点的坐标均为整数。现在他想知道：有多少个边与坐标轴平行的正方形，其四个顶点上均画有点？请帮助他计算这个数目。

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.

第一行包含一个整数 $n$（$1 \leq n \leq 10^5$）。接下来的 $n$ 行中，每行包含两个整数 $x_i$、$y_i$（$0 \leq x_i, y_i \leq 10^5$），表示第 $i$ 个点的坐标。保证所有给定的点互不相同。

In a single line print the required number of squares.

在一行中输出所需正方形的数量。