import sys
sys.setrecursionlimit(5*10**5)
input = sys.stdin.readline
from collections import defaultdict, deque, Counter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right
from math import gcd
n = int(input())
xy = [list(map(int,input().split())) for i in range(n)]

ans = 0
for i in range(n):
    d = defaultdict(int)
    xi,yi = xy[i]
    mx = 0
    for j in range(n):
        if i==j: continue
        xj,yj = xy[j]
        g = gcd(abs(xi-xj), abs(yi-yj))
        d[((xi-xj)//g, (yi-yj)//g)] += 1
        mx = max(mx, d[((xi-xj)//g, (yi-yj)//g)])
    ans += mx >= 2
print(ans)