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();
        int xstart=0;
        int ystart=0;
        int flagx=1;
        int flagy=1;
        for(int i = 0; i < n; i++){
            int x = in.nextInt();
            int y = in.nextInt();
            if(i==0){
                xstart = x;
                ystart = y;
            }else{
                if(x!=xstart){
                    flagx=0;
                }if(y!=ystart){
                    flagy=0;
                }
            }
        }
        if(flagx==1 || flagy==1){
            System.out.println("YES");
        }else{
            System.out.println("NO");
        }
    }
}