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

int main()
{   
	int n,freq_x=-1,freq_y=-1,x_x,y_y;
	
	cin>>n;

	while(n--){
		int x,y;
		cin>>x>>y;

		if(freq_x!=0){

		if(freq_x==-1){
			x_x = x;
			freq_x=1;
		}

		else {
			if(x_x!=x)
				freq_x = 0;
		}
	}

	if(freq_y!=0){

		if(freq_y==-1){
			freq_y=1;
			y_y = y;
		}
		else
		{
			if(y_y!=y)
				freq_y=0;
		}
	}



	}

	if(freq_y || freq_x)
		cout<<"YES";
	else
		cout<<"NO";

	return 0;
}