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