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.
The first line contains integer *n* (1 ≤ *n* ≤ 2000) — the number of the points painted on the plane. 

Next *n* lines contain two integers each *x*<sub class="lower-index">*i*</sub>, *y*<sub class="lower-index">*i*</sub> ( - 100 ≤ *x*<sub class="lower-index">*i*</sub>, *y*<sub class="lower-index">*i*</sub> ≤ 100) — the coordinates of the *i*-th point. It is guaranteed that no two given points coincide.
import itertools

def dependency(ss):
    area = ss[0][0]*(ss[1][1]-ss[2][1]) + ss[1][0]*(ss[2][1]-ss[0][1]) + ss[2][0]*(ss[0][1]-ss[1][1])
    if area == 0 :
        return False
    return True

n = int(input())
pos = []
if n < 3:
    print(0)
    exit(0)
for i in range(n):
    x, y = map(int,input().split())
    pos.append((x ,y))

max = 0

for subset in itertools.combinations(pos, 3):
    if dependency(subset):
        max = max + 1
print(max)
