## Another Contest 9 Problem 5 - Satellite

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Points: 12
Time limit: 1.0s
Memory limit: 256M

Problem types

From atop a satellite, Nick has drawn lines on the surface of a plane, no three of which intersect at a common point. He counts many triangles, but how many of them contain no triangles with a strictly smaller area?

#### Constraints

All lines are pairwise distinct.

No three lines intersect at a common point.

#### Input Specification

The first line contains a single positive integer, .

The next lines contain four space-separated integers, , , , , indicating a line going through distinct points and .

#### Output Specification

Output the number of such triangles.

#### Sample Input

4
0 0 0 10
0 0 10 0
0 5 5 5
0 10 10 0

#### Sample Output

1