N=int(input())
A=[]
for _ in range(N):
  x,y=map(int, input().split())
  A.append((x,y))
  
import math
ans=0
for i in range(N):
  ax,ay=A[i]
  D=[]
  for j in range(N):
    if i==j:
      continue
    bx,by=A[j]
    x,y=bx-ax,by-ay
    if x==0 and y>0:
    	D.append((0,1))
    elif x==0 and y<0:
    	D.append((0,-1))
    elif x>0 and y==0:
    	D.append((1,0))
    elif x<0 and y==0:
    	D.append((-1,0))
    else:
    	d=math.gcd(abs(x),abs(y))
    	x//=d;y//=d
    	D.append((x,y))
  if len(D)!=len(set(D)):
  	ans+=1
print(ans)