from math import gcd
n = int(input())
xy = [tuple(map(int,input().split())) for _ in range(n)]
ans = 0
for i,(ix,iy) in enumerate(xy):
    s = set()
    for j,(jx,jy) in enumerate(xy):
        dx = ix-jx; dy = iy-jy
        if dx==dy==0: s.add((0,0))
        elif dx==0: s.add((0,dy//abs(dy)))
        elif dy==0: s.add((dx//abs(dx),0))
        else: g = gcd(abs(dx),dy); s.add((dx//g,dy//g))
    if len(s)<n: ans += 1
print(ans)