n = int(input())
xy = [tuple(map(int,input().split())) for _ in range(n)]

if n == 2:
    print(1)
    exit(0)

b = [1]*n
b[0] = 0
min_dist = 10**18
for i in range(n):
    xi,yi = xy[i]
    if i == 0: 
        for j in range(n):
            if i == j: continue
            xj,yj = xy[j]
            min_dist = min(min_dist,(xi-xj)**2+(yi-yj)**2)
    else:
        for j in range(n):
            if i == j: continue
            xj,yj = xy[j]
            tmp_dist = (xi-xj)**2+(yi-yj)**2
            if tmp_dist <= min_dist:
                b[i] = 0
                b[j] = 0

print(sum(b))