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();
        }
        
        int x0 = x[0];
        int y0 = y[0];
        boolean h = true;
        boolean v = true;
        
        for (int i = 1; i < n; i++) {
            if (x0 != x[i])
                h = false;
            if (y0 != y[i])
                v = false;
        }
        
        if (h || v) 
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}