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[] xs = new int[n];
        int[] ys = new int[n];
        boolean xsame = true;
        boolean ysame = true;
        for(int a0 = 0; a0 < n; a0++){
            xs[a0] = in.nextInt();
            ys[a0] = in.nextInt();
        }
        int x0 = xs[0];
        int y0 = ys[0];
        for (int i = 1; i < n; i++)
            {
            if (xs[i] != x0)
                {
                xsame = false;
            }
            if (ys[i] != y0)
                {
                ysame = false;
            }
            if (!xsame && !ysame)
                {
                System.out.println("NO");
                return;
            
            }
        }
        System.out.println("YES");
    }
}