Monochromatic Triangles

Memory limit: 32 MB

There are points given in a space. There are no three points, such that they lie on the same straight line. Each pair of points is connected by a segment coloured red or black. Each triangle, whose sides have the same colour is called a monochromatic triangle. We are given a list of all red segments and we want to find the number of all monochromatic triangles.

Task

Write a program that:

• reads from the standard input the following data: the number of points, the number of red segments and their list,
• finds the number of monochromatic triangles,
• writes the result to the standard output.

Input

In the first line of the standard input there is one integer , , which equals the number of points. In the second line there is one integer , , which equals the number of red segments.

In each of the following lines there are two integers and separated by a single space, . They are numbers of vertices which are ends of a red segment.

Output

In the first line of the standard output there should be written one integer — the number of monochromatic triangles.

Example

For the input data:

6
9
1 2
2 3
2 5
1 4
1 6
3 4
4 5
5 6
3 6

the correct result is:

2

Task author: Wojciech Guzicki.