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[] xvals = new int[n];
        int[] yvals = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            xvals[a0] = in.nextInt();
            yvals[a0] = in.nextInt();
        }
        int xtest = xvals[0];
        int ytest = yvals[0];
        Boolean xflag = true;
        Boolean yflag = true;
        for (int i = 1; i < n; i++)
        {
            if (xtest != xvals[i])
                xflag = false;
            if (ytest != yvals[i])
                yflag = false;
        }
        if (xflag == true || yflag == true)
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}