#include <bits/stdc++.h>
using namespace std;
int main() {
	int n;
	cin >> n;
	int x[n], y[n];
	set<int> s1, s2;
	for(int i = 0; i < n; i++) cin >> x[i] >> y[i], s1.insert(x[i]), s2.insert(y[i]);
	if(int(s1.size()) == 1 || int(s2.size()) == 1) cout << "YES\n";
	else cout << "NO\n";
}