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 lastX = 0;
        int lastY = 0;
        boolean isHorizontal = true;
        boolean isVertical = true;
        
        for(int a0 = 0; a0 < n; a0++) {
            int x = in.nextInt();
            int y = in.nextInt();
            if (a0 > 0) {
                isHorizontal &= x == lastX;
                isVertical &= y == lastY;
            }
            lastX = x;
            lastY = y;        
        }
        
        System.out.println((isHorizontal || isVertical) ? "YES" : "NO");
    }
}