#include <bits/stdc++.h>
using namespace std;

typedef unsigned short usint;
typedef unsigned uint;
typedef unsigned long ulint;
typedef unsigned long long ullint;
typedef long long llint;

#define mp make_pair

int main() { ios_base::sync_with_stdio(0);

	int n;
	cin >> n;
	vector <pair <int, int>> vp;
	int x, y;

	for (int t1 = 0; t1 < n; ++t1) {
		cin >> x >> y;
		vp.push_back(mp(x, y));
	}

	sort(vp.begin(), vp.end());
	bool hor = true;
	bool ver = true;

	for (int t1 = 1; t1 < n; ++t1) {
		if (vp[t1].first != vp[t1-1].first)
			ver = false;
		if (vp[t1].second != vp[t1-1].second)
			hor = false;
	}

	if (hor+ver)
		cout << "YES\n";
	else cout << "NO\n";




	return 0;
}