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[] a = new int[n], b = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            a[a0] = x;
            b[a0] = y;
        }
        
        boolean linex = true, liney = true;
        
        for(int i = 0; i < n; ++i) {
            if(a[i] != a[0]) {
                linex = false;
            }
            if(b[i] != b[0]) {
                liney = false;
            }
        }
        
        if(linex || liney) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
}