import sys
input = sys.stdin.readline

from math import gcd
from operator import itemgetter

N=int(input())
XY=[list(map(int,input().split())) for i in range(N)]


def angle(a,b,c,d):
    x,y=a-c,b-d

    if x==0:
        return (0,1)
    if y==0:
        return (1,0)

    if x<0:
        x=-x
        y=-y

    g=abs(gcd(x,y))

    x//=g
    y//=g

    return (x,y)

        

USE=[0]*N

for i in range(N):
    D=dict()
    for j in range(N):
        if i==j:
            continue

        a,b=XY[i]
        c,d=XY[j]

        k=angle(a,b,c,d)

        if k in D:
            D[k].append(j)
        else:
            D[k]=[j]

    #print("!",D)

    for d in D:
        if len(D[d])<=1:
            continue

        LIST=[(XY[i][0],XY[i][1],i)]

        for d in D[d]:
            LIST.append((XY[d][0],XY[d][1],d))

        LIST.sort(key=itemgetter(0))
        LIST.sort(key=itemgetter(1))

        #print(d,LIST)

        for j in range(2,len(LIST)):
            USE[LIST[j][2]]=1

        for j in range(len(LIST)-3,-1,-1):
            USE[LIST[j][2]]=1

print(sum(USE))