import sys
from collections import deque
from fractions import Fraction as frac
input = sys.stdin.readline
INF = 10 ** 9

class Point:
	def __init__(self, x: frac, y: frac):
		self.x = x
		self.y = y

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

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

	def __lt__(self, other):
		if(self.x == other.x):
			return (self.y < other.y)
		return (self.x < other.x)

	def show(self):
		print(self.x, self.y)

	def calcLine(self, other):
		x1 = self.x;  y1 = self.y
		x2 = other.x;  y2 = other.y
		if(x1 == x2):
			return Line(frac(1), frac(0), x1)
		a = (y1 - y2) / (x1 - x2)
		c = y1 - a * x1
		return Line(-a, frac(1), c)

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

	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))

	def show(self):
		print((self.a, self.b, self.c))

	def intersection(self, other) -> Point:
		p = self.a * other.b - other.a * self.b
		if(p == frac(0)):
			return None
		q = other.b * self.c - self.b * other.c
		x = q / p
		y = (other.c - other.a * x) / other.b if(self.b == 0) else (self.c - self.a * x) / self.b
		return Point(x, y)


"""
Main Code
"""


N = int(input())
P = [Point(*map(frac, input().split())) for _ in [0] * N]

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

ph = {}
pt_id = 0
for p in P:
	ph[p] = pt_id
	pt_id += 1

ln_id = 0
lh = {}
for i in range(N - 1):
	for j in range(1, N):
		p1, p2 = P[i], P[j]
		l = p1.calcLine(p2)
		if(l in lh):
			continue
		lh[l] = ln_id
		ln_id += 1

lis = list(lh.keys())
for i in range(ln_id - 1):
	for j in range(1, ln_id):
		l1, l2 = lis[i], lis[j]
		p = l1.intersection(l2)
		if(p is None or p in ph):
			continue
		P.append(p)
		ph[p] = pt_id
		pt_id += 1

dir_lis = [[None]*pt_id for _ in [0]*pt_id]
for i in range(pt_id - 1):
	for j in range(1, pt_id):
		p1, p2 = P[i], P[j]
		l = p1.calcLine(p2)
		if(l not in lh):
			continue
		dir_lis[i][j] = (lh[l], (p1 < p2))
		dir_lis[j][i] = (lh[l], (p2 < p1))

dp = [[[[INF]*2 for _ in [0]*(ln_id + 1)] for _ in [0]*pt_id] for _ in [0]*(1 << N)]
que = deque([])
for i in range(N):
	que.append((0, 1 << i, i, ln_id, 0))
	dp[1 << i][i][ln_id][0] = 0
goal = (1 << N) - 1
ans = INF
cnt = 0
while(que):
	c, b, v, l, a = que.popleft()
	if(c > dp[b][v][l][a]):
		continue
	if(b == goal):
		ans = c
		break
	for nv in range(pt_id):
		nb = b
		if(nv < N):
			nb = b | (1 << nv)
		if(dir_lis[v][nv] is None):
			continue
		nl, na = dir_lis[v][nv]
		nc = c
		if(l is None or (l, a) != (nl, na)):
			nc += 1
		if(nc >= dp[nb][nv][nl][na]):
			continue
		dp[nb][nv][nl][na] = nc
		if(nc == c):
			que.appendleft((nc, nb, nv, nl, na))
		else:
			que.append((nc, nb, nv, nl, na))
print(ans)