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

int main() {
	int n; cin >> n;
	int tx, ty; cin >> tx >> ty;
	for (int i = 1; i < n; i++) {
		int x, y; cin >> x >> y;
		if (x != tx) tx = 1e9;
		if (y != ty) ty = 1e9;
	}
	if (tx <= 10 || ty <= 10) puts("YES");
	else puts("NO");
	return 0;
}