Author:  A. Baranov  Time limit:  1 sec  
Input file:  Standard input  Memory limit:  256 Mb  
Output file:  Standard output 
Let's consider a configuration of n lines on a plane. The task is to count the maximum number of triangle cells formed as a result of subdivison plane by these lines.
The input begins with a natural number n, followed by exactly n lines. Each line is defined by a pair of distinct points: (Ax_{i}, Ay_{i}), (Bx_{i}, By_{i}).
The output should contain the number of triangles obtained.
It is guaranteed that no two lines coincide.
All input values are integers.
− 10^{4} ≤ (Ax_{i}, Ay_{i}, Bx_{i}, By_{i}) ≤ 10^{4}, 3 ≤ n ≤ 300
No.  Standard input  Standard output 

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