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 points[][] = new int[n][2];
		boolean xflag = true;
		boolean yflag = true;
		int x = in.nextInt();
		int y = in.nextInt();
		int a0 = 0;
		points[a0][0] = x;
		points[a0][1] = y;
		/*for (a0=1; a0 < n; a0++) {
			points[a0][0] = in.nextInt();
			points[a0][1] = in.nextInt();
		}
		for(int i=0;i<n;i++) {
			
		}
		 */
		for (a0 = 1; a0 < n; a0++) {
			int x1 = in.nextInt();
			int y1 = in.nextInt();
			if (x != x1)
				xflag = false;
			if (y != y1)
				yflag = false;
			x = x1;
			y = y1;
		}
		if (xflag || yflag)
			System.out.println("YES");
		else
			System.out.println("NO");
		in.close();
	
    }
}