Vanya got bored and he painted n distinct points on the plane. After that he connected all the points pairwise and saw that as a result many triangles were formed with vertices in the painted points. He asks you to count the number of the formed triangles with the non-zero area.
Output
In the first line print an integer − the number of triangles with the non-zero area among the painted points.
Note
Note to the first sample test. There are
3 triangles formed:
(0,0)-(1,1)-(2,0);
(0,0)-(2,2)-(2,0);
(1,1)-(2,2)-(2,0).
Note to the second sample test. There is
1 triangle formed:
(0,0)-(1,1)-(2,0).
Note to the third sample test. A single point doesn't form a single triangle.