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.
def main():

    n = map(int, input().split())
    total = 0
    x = []
    y = []
    lines = {}

    for i in range(n):
        x[i], y[i] = map(int, input().split())

    for j in range(n - 2):
        for k in range(n - 1):
            for m in range(n):
                test = x[j] * (y[k] - y[m]) + x[k] * (y[m] - y[j]) + x[m] * (y[j] - y[k])
                if (test != 0):
                    total += 1

    print(total)


if __name__ == '__main__':
    main()