import java.io.*; import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*; public class Solution { public static void main(String[] args) { Scanner in = new Scanner(System.in); int n = in.nextInt(); Set xSet = new TreeSet(); Set ySet = new TreeSet(); for(int a0 = 0; a0 < n; a0++){ int x = in.nextInt(); int y = in.nextInt(); xSet.add(x); ySet.add(y); } if(xSet.size()==1 || ySet.size()==1) System.out.println("YES"); else System.out.println("NO"); in.close(); } }