### COCI 2007/2008, Contest #3

## Task DEJAVU

N points are placed in the coordinate plane.

Write a program that calculates how many ways we can choose three points so that they form a **right**
triangle with **legs** parallel to the coordinate axes.

A right triangle has one 90-degree internal angle. The legs of a right triangle are its two shorter sides.

### Input

The first line of input contains the integer N (3 ≤ N ≤ 100 000), the number of points.

Each of the following N lines contains two integers X and Y (1 ≤ X, Y ≤ 100 000), the coordinates of one point.

No pair of points will share the same pair of coordinates.

### Output

Output the number of triangles.

### Scoring

In 40% of all test cases, N will be less than 100.

In 70% of all test cases, N will be less than 10 000.

### Examples

## Input3 4 2 2 1 1 3 ## Output0 |
## Input5 1 2 2 1 2 2 2 3 3 2 ## Output4 |
## Input6 10 10 20 10 10 20 20 20 30 20 30 30 ## Output8 |

All Submissions

Best Solutions

**Point Value:** 7 (partial)

**Time Limit:** 1.00s

**Memory Limit:** 32M

**Added:** Jul 30, 2013

**Languages Allowed:**

C++03, PAS, C, HASK, ASM, RUBY, PYTH2, JAVA, PHP, SCM, CAML, PERL, C#, C++11, PYTH3

## Comments (Search)

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