import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    private static boolean isSameValues(int[] arr) {
        for (int i = 0; i < arr.length - 1; i++) {
            if (arr[i] != arr[i+1]) {
                return false;
            }
        }
        return true;
    }
    
    private static boolean isSameLine(int[] xs, int[] ys) {
        if (isSameValues(xs)) {
            return true;
        } else if (isSameValues(ys)) {
            return true;
        } else {
            return false;
        }
    }
    
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] xcoords = new int[n];
        int[] ycoords = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            xcoords[a0] = x;
            ycoords[a0] = y;
        }
        System.out.println(isSameLine(xcoords, ycoords) ? "YES": "NO");
    }
}