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

ans=0
import math
for i in range(n):
  s=set()
  flag=False
  for j in range(n):
    if i==j:
      continue
    xi,yi=xy[i]
    xj,yj=xy[j]
    dx=xj-xi
    dy=yj-yi
    g=math.gcd(dx,dy)
    dx//=g
    dy//=g
    if (dx,dy) in s:
      flag=True
    else:
      s.add((dx,dy))
  if flag:
    ans+=1
print(ans)