TASK A

#include <bits/stdc++.h>
#include <algorithm>

using namespace std;

using ll = long long;
set<pair<int,int>> cords;
constexpr int INF = 1e9+7;

pair<int,int> getK(pair<int, int> a, pair<int, int> b) {
	a.first -= b.first;
	a.second -= b.second;
	int g = __gcd(abs(a.first), abs(a.first));
	if (g != 0)
	{
		a.first /= g;
		a.second /= g;
	}
  if (a.first == a.second && a.first==0)
    return{INF, INF};
	if (a.first == 0)
		a.second = 1;
	if (a.second == 0)
		a.first = 1;
	return { a.first, a.second };
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;
	pair<int, int> point;
	while(n--)
  {
    cin >> point.first >> point.second;
    cords.insert(point);
  }
	pair<int, int> k = getK(*cords.begin(), *cords.rbegin());
	int check = 0;
	for (auto el: cords) {
		if (k != (getK(*cords.begin(), el)==make_pair(INF, INF)?k:getK(*cords.begin(), el))) {
			check = 1;

			break;
		}
	}
	check ? cout << "no" : cout << "yes";
	return 0;
}