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[] xVal = new int[n];
        int[] yVal = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            
            xVal[a0] = x;
            yVal[a0] = y;
        }
        
        boolean outCome = true;
        
        int val = xVal[0];
        for (int i = 1; i < n; i++) {
            if (val != xVal[i]) {
                outCome = false;
                break;
            }
        }
        
        if (!outCome) {
            val = yVal[0];
            for (int i = 1; i < n; i++) {
                if (val != yVal[i]) {
                    outCome = false;
                    break;
                }
            }
        }
        
        System.out.println(outCome ? "YES" : "NO");
    }
}