N=int(input())
A=[]
for i in range(N):
  x,y=map(int, input().split())
  A.append((x,y,i))
D=[[-1]*N for _ in range(N)]
E=[0]*N
for i in range(N-1):
  for j in range(i+1,N):
    if D[i][j]==1:
      continue 
    D[i][j]=1
    x1,y1,p=A[i];x2,y2,q=A[j]
    C=[]
    C.append(A[i])
    C.append(A[j])
    for k in range(j+1,N):
      x3,y3,r=A[k]
      if (y3-y1)*(x2-x1)==(x3-x1)*(y2-y1):
        C.append(A[k])
        D[i][k]=1;D[j][k]=1
    if len(C)>=4:
      for _,_,a in C:
        E[a]=1
    if len(C)==3:
      C=sorted(C,key=lambda x: x[1]) 
      C=sorted(C,key=lambda x: x[0]) 
      E[C[0][-1]]=1
      E[C[-1][-1]]=1
print(sum(E))