import sys

sys.setrecursionlimit(10**6)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.buffer.readline())
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def LI1(): return list(map(int1, sys.stdin.buffer.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def BI(): return sys.stdin.buffer.readline().rstrip()
def SI(): return sys.stdin.buffer.readline().rstrip().decode()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = 10**16
md = 998244353
# md = 10**9+7

class v:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def zone(self, v):
        x = v.x
        y = v.y
        if x > 0 and y >= 0: return 1
        if x <= 0 and y > 0: return 2
        if x < 0 and y <= 0: return 3
        return 4

    def rev(self):
        return v(-self.x, -self.y)

    def __mul__(self, other):
        return self.x*other.y-self.y*other.x

    def __eq__(self, other):
        return self*other == 0 and self.zone(self) == self.zone(other)

    def __lt__(self, other):
        z1 = self.zone(self)
        z2 = self.zone(other)
        if z1 < z2: return True
        if z1 > z2: return False
        return self*other > 0

    def __repr__(self):
        return f"({self.x},{self.y})"

from bisect import *

n = II()
vv = []
for _ in range(n):
    x, y = LI()
    vv.append(v(x, y))
vv.sort()
# print(vv)

ans = 0
for j in range(n):
    for i in range(j):
        v1 = vv[i].rev()
        v2 = vv[j].rev()
        if v1*v2 == 0: continue
        if v1*v2 < 0: v1, v2 = v2, v1
        l = bisect_right(vv, v1)
        r = bisect_left(vv, v2)
        if l <= r: ans += r-l
        else: ans += n-l+r
        # print(v1, v2, l, r, ans)

print(ans//3)