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[] arrX = new int[n];
        int[] arrY = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            arrX[a0] = x;
            arrY[a0] = y;
        }
        System.out.println(allOnLine(arrX, arrY));
    }
    
    private static String allOnLine(int[] arrX, int[] arrY) {
        int presentX = arrX[0];
        int presentY = arrY[0];
        boolean allV = true;
        boolean allH = true;
        for(int i = 1; i < arrX.length; i++) {
            int nextX = arrX[i];
            int nextY = arrY[i];
            if(presentX != nextX) {
                allV = false;
            }
            if(presentY != nextY) {
                allH = false;
            }
            presentX = nextX;
            presentY = nextY;
        }
        if(allV || allH) {
            return "YES";
        }
        return "NO";
    }
}