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

bool solve() {
	int n;
	cin >> n;

	vector<int> xs(n), ys(n);
	for (int i = 0; i < n; i++) cin >> xs[i] >> ys[i];
	if (set<int>(xs.begin(), xs.end()).size() == 1) return true;
	if (set<int>(ys.begin(), ys.end()).size() == 1) return true;
	return false;
}

int main() {
	puts(solve() ? "YES" : "NO");
}