from __future__ import annotations
import itertools as iter
import collections as coll
import heapq as hq
import bisect as bis
from decimal import Decimal as dec
from functools import cmp_to_key
import math
import sys
#import pypyjit
#pypyjit.set_param('max_unroll_recursion=-1')
sys.setrecursionlimit(10 ** 6)
inp = sys.stdin.readline
input = lambda : inp().rstrip()
getN = lambda : int(inp())
getNs = lambda : map(int, inp().split())
getList = lambda :list(map(int, inp().split()))
getStrs = lambda n : [input() for _ in [0] * n]
def yexit(): print("Yes"); exit(0)
def nexit(): print("No"); exit(0)
pi = 3.141592653589793
mod = 1000000007
MOD = 998244353
INF = 4611686018427387903
dx = [1, 0, -1, 0];	dy = [0, 1, 0, -1]
#di = coll.defaultdict(int)

from fractions import Fraction as frac
class Vector2:
	def __init__(self, x, y):
		self.x = x
		self.y = y

	def __str__(self):
		return str((float(self.x), float(self.y)))

	__repr__ = __str__

	def __eq__(self, other):
		return (self.x == other.x and self.y == other.y)

	def __hash__(self):
		return hash((self.x, self.y))

	def __sub__(self, other):
		return Vector2(other.x - self.x, other.y - self.y)

	def normalize(self) -> Vector2:
		if(self.x == 0 and self.y == 0):
			return self
		norm = self.x ** 2 + self.y ** 2
		self.x *= abs(self.x) / norm
		self.y *= abs(self.y) / norm
		return self


class Line:
	def __init__(self, a, b, c):
		self.a = a
		self.b = b
		self.c = c

	def __str__(self):
		return str((self.a, self.b, self.c))

	__repr__ = __str__

	def __eq__(self, other):
		return (self.a == other.a and self.b == other.b and self.c == other.c)

	def __hash__(self):
		return hash((self.a, self.b, self.c))
	
	@classmethod
	def calc_line(cls, one: Vector2, other: Vector2) -> Line:
		if(one == other):
			return None
		x1 = one.x;  y1 = one.y
		x2 = other.x;  y2 = other.y
		if(x1 == x2):
			return Line(1, 0, x1)
		a = (y1 - y2) / (x1 - x2)
		c = y1 - a * x1
		return Line(-a, 1, c)

	@classmethod
	def calc_intersection(cls, one: Line, other: Line) -> Vector2:
		p = one.a * other.b - other.a * one.b
		if(p == 0):
			return None
		q = other.b * one.c - one.b * other.c
		x = q / p
		y = (other.c - other.a * x) / other.b if(one.b == 0) else (one.c - one.a * x) / one.b
		return Vector2(x, y)

"""
Main Code
"""

N = getN()
P = [Vector2(*map(frac, inp().split())) for _ in [0]*N]

if(N == 1):
	print(1)
	exit(0)

line_set = set([])
for p1, p2 in iter.combinations(P, 2):
	line_set.add(Line.calc_line(p1, p2))
	
point_set = set(P)
point_num = N
for l1, l2 in iter.combinations(line_set, 2):
	p = Line.calc_intersection(l1, l2)
	if(p is None or p in point_set):
		continue
	point_set.add(p)
	P.append(p)
	point_num += 1

vec_lis = [[None]*point_num for _ in [0]*point_num]
for i in range(point_num - 1):
	for j in range(i + 1, point_num):
		if(Line.calc_line(P[i], P[j]) not in line_set):
			continue
		vec_lis[i][j] = (P[j] - P[i]).normalize()
		vec_lis[j][i] = (P[i] - P[j]).normalize()

mbit = 1 << N
goal = mbit - 1
dp = [[[N]*point_num for _ in [0]*point_num] for _ in [0]*mbit]
que = coll.deque([])
for i in range(N):
	bit = 1 << i
	dp[bit][i][i] = 0
	que.append((bit, i, i, 0))
while(que):
	b_now, v_prev, v_now, c_now = que.popleft()
	if(c_now > dp[b_now][v_prev][v_now]):
		continue
	if(b_now == goal):
		print(c_now)
		break
	for v_next in range(point_num):
		if(v_next in [v_prev, v_now] or min(v_now, v_next) >= N):
			continue
		if(vec_lis[v_now][v_next] is None):
			continue
		b_next = b_now | (1 << v_next) if(v_next < N) else b_now
		c_next = c_now + (v_prev == v_now or vec_lis[v_prev][v_now] != vec_lis[v_now][v_next])
		if(c_next >= dp[b_next][v_now][v_next]):
			continue
		dp[b_next][v_now][v_next] = c_next
		if(c_now == c_next):
			que.appendleft((b_next, v_now, v_next, c_next))
		else:
			que.append((b_next, v_now, v_next, c_next))