#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int gcd(int x, int y) {
	if(y == 0) return x;
	return gcd(y, x % y);
}
int main() {
	int N;
	cin >> N;
	vector<int> X(N), Y(N);
	for(int i = 0; i < N; ++i) {
		cin >> X[i] >> Y[i];
	}
	vector<vector<int> > lines; // {a, b, c} --> ax + by + c = 0
	for(int i = 0; i < N; ++i) {
		for(int j = 0; j < i; ++j) {
			int a = Y[i] - Y[j];
			int b = -(X[i] - X[j]);
			int c = -(a * X[i] + b * Y[i]);
			int g = gcd(abs(a), gcd(abs(b), abs(c)));
			if(a < 0 || (a == 0 && b < 0)) {
				a *= -1, b *= -1, c *= -1;
			}
			lines.push_back({a / g, b / g, c / g});
		}
	}
	sort(lines.begin(), lines.end());
	lines.erase(unique(lines.begin(), lines.end()), lines.end());
	int ls = lines.size();
	vector<bool> ok(1 << N, false);
	ok[0] = true;
	for(int i = 0; i < N; ++i) {
		ok[1 << i] = true;
	}
	vector<vector<pair<int, int> > > cand(ls);
	for(int i = 0; i < ls; ++i) {
		vector<int> orth;
		for(int j = 0; j < N; ++j) {
			if(lines[i][0] * X[j] + lines[i][1] * Y[j] + lines[i][2] == 0) {
				orth.push_back(lines[i][1] * X[j] - lines[i][0] * Y[j]);
			}
		}
		for(int j : orth) {
			for(int b = 0; b < 2; ++b) {
				int bit = 0;
				for(int k = 0; k < N; ++k) {
					int val = lines[i][0] * X[k] + lines[i][1] * Y[k] + lines[i][2];
					if(val == 0) {
						val += (lines[i][1] * X[k] - lines[i][0] * Y[k] >= j ? +1 : -1) * ((b & 1) ? +1 : -1);
					}
					if(val > 0) bit |= 1 << k;
				}
				cand[i].push_back(make_pair(+1, bit));
				cand[i].push_back(make_pair(-1, (1 << N) - 1 - bit));
			}
		}
	}
	for(int i = 0; i < ls; ++i) {
		for(int j = 0; j <= i; ++j) {
			if(lines[i][0] * lines[j][1] != lines[i][1] * lines[j][0]) continue;
			for(int k = 0; k < ls; ++k) {
				for(pair<int, int> ci : cand[i]) {
					for(pair<int, int> cj : cand[j]) {
						for(pair<int, int> ck : cand[k]) {
							ok[ci.second & cj.second & ck.second] = true;
						}
					}
				}
			}
		}
	}
	for(int i = 0; i < ls; ++i) {
		for(int j = 0; j < i; ++j) {
			for(int k = 0; k < j; ++k) {
				if(lines[i][0] * lines[j][1] == lines[i][1] * lines[j][0]) continue;
				if(lines[j][0] * lines[k][1] == lines[j][1] * lines[k][0]) continue;
				if(lines[k][0] * lines[i][1] == lines[k][1] * lines[i][0]) continue;
				vector<int> pos = { i, j, k };
				vector<int> sign(3);
				bool nonzero = true;
				for(int w = 0; w < 3; ++w) {
					int p0 = pos[w], p1 = pos[(w + 1) % 3], p2 = pos[(w + 2) % 3];
					long long val0 = 1LL * lines[p0][2] * (lines[p2][0] * lines[p1][1] - lines[p1][0] * lines[p2][1]);
					long long val1 = 1LL * lines[p1][2] * (lines[p0][0] * lines[p2][1] - lines[p2][0] * lines[p0][1]);
					long long val2 = 1LL * lines[p2][2] * (lines[p0][0] * lines[p1][1] - lines[p1][0] * lines[p0][1]);
					long long val = (val0 + val1 - val2) * (lines[p2][0] * lines[p1][1] - lines[p1][0] * lines[p2][1] > 0 ? +1 : -1);
					if(val == 0) {
						nonzero = false;
						break;
					}
					sign[w] = (val > 0 ? +1 : -1);
				}
				if(!nonzero) continue;
				for(pair<int, int> ci : cand[i]) {
					if(ci.first != sign[0]) continue;
					for(pair<int, int> cj : cand[j]) {
						if(cj.first != sign[1]) continue;
						for(pair<int, int> ck : cand[k]) {
							if(ck.first != sign[2]) continue;
							ok[ci.second & cj.second & ck.second] = true;
						}
					}
				}
			}
		}
	}
	int res = 0;
	for(int i = 0; i < (1 << N); ++i) {
		if(ok[i]) {
			++res;
		}
	}
	cout << res << endl;
	return 0;
}