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[] xValues=new int[n];
        int[] yValues= new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            xValues[a0]=x;
            yValues[a0]=y;
        }
        int x0=xValues[0];
        int y0=yValues[0];
        boolean xflag=true;
        boolean yflag=true;
        for(int i=0;i<n;i++){
            if(xValues[i]!=x0){
                xflag=false;
            }
            if(yValues[i]!=y0){
                yflag=false;
            }
        }
        if(xflag||yflag){
            System.out.println("YES");
        }else{
            System.out.println("NO");
        }
    }
}