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 math
from math import sqrt, inf
import queue


# -------- info --------

# https://codeforces.com/profile/Wolxy

# -------- sys --------

def dis(from_loc, to_loc, euclidean = True) -> int:
    result = 0
    if euclidean:
        for i in range(min(len(from_loc), len(to_loc))):
            result += (from_loc[i] - to_loc[i]) * (from_loc[i] - to_loc[i])
    else:
        for i in range(min(len(from_loc), len(to_loc))):
            result += from_loc[i] - to_loc[i]
    return result


def product(from_loc, first_loc, second_loc) -> int:
    vector1 = (first_loc[0] - from_loc[0], first_loc[1] - from_loc[1])
    vector2 = (second_loc[0] - from_loc[0], second_loc[1] - from_loc[1])
    return vector1[0] * vector2[1] - vector2[0] * vector1[1]

# -------- functions[clearable] --------


# -------- solve[clearable] --------

def solve() -> None:
    n = int(input())
    ls = []
    for _ in range(n):
        ls.append(tuple(map(int, input().split(' '))))
    count = 0
    for i in range(n):
        for j in range(i + 1, n):
            for k in range(j + 1, n):
                if product(ls[i], ls[j], ls[k]) != 0:
                    count += 1
    print(count)


# -------- main --------


T = 1
# T = int(input())
for _ in range(T):
    solve()
