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[] xArr = new int[n];
        int[] yArr = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            xArr[a0] = x;
            yArr[a0] = y;
        }
        boolean xSame = true;
        boolean ySame = true;
        for(int i = 1; i < n; i++){
            if(xArr[i] != xArr[i-1]){
                xSame = false;
                break;
            }
                
        }
        for(int j = 1; j < n; j++){
            if(yArr[j] != yArr[j-1]){
                ySame = false;
                break;
            }
        }
        if((xSame && !ySame) || (!xSame && ySame))
               System.out.println("YES");
               else
               System.out.println("NO");
    }
}