## https://yukicoder.me/problems/no/2355


def calc_gcd(A, B):
    """
    正の整数A, Bの最大公約数を計算する
    """
    a = max(A, B)
    b = min(A, B)
    while a % b > 0:
        c = a % b
        a = b
        b = c
    return b

def main():
    N = int(input())
    xy = []
    for _ in range(N):
        x, y = map(int, input().split())
        xy.append((x, y))
    
    answer = 0
    for i in range(N):
        x0, y0 = xy[i]
        a_map = {}
        for j in range(N):
            if i == j:
                continue

            x1, y1 = xy[j]
            dx = x1 - x0
            dy = y1 - y0

            if dx == 0:
                dy = dy // abs(dy)
            elif dy == 0:
                dx = dx // abs(dx)
            else:
                gcd = calc_gcd(abs(dx), abs(dy))
                dx //= gcd
                dy //= gcd
            if (dx, dy) not in a_map:
                a_map[(dx, dy)] = 0
            a_map[(dx, dy)] += 1
        
        if len(a_map) > 0:
            ans = max(a_map.values())
            if ans >= 2:
                answer += 1
    print(answer)
    








if __name__ == "__main__":
    main()