#include <bits/stdc++.h>
using namespace std;
#define ll long long int;
int main()
{
	int n;
	cin >> n;
	vector<int> x(n);
	vector<int> y(n);
	int cx = 0, cy = 0;

		cin >> x[0] >> y[0];
	for(int i = 1 ; i < n; i++) {
		int a, b;
		cin >> x[i] >> y[i];
		if((x[i] - x[i-1]) == 0)
			cx++;
		if((y[i] - y[i-1])== 0)
			cy++;
	}
	if(cx == n-1 && cy  == n-1)
		cout << "NO" << endl;
	else if(cx == n-1 || cy == n-1)
		cout << "YES" << endl;
	else 
		cout << "NO" << endl;
	return 0;
}