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