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 x1=in.nextInt();
        int y1=in.nextInt();
        boolean flag1=true,flag2=true;
        for(int a0 = 1; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            if(x!=x1)
                flag1=false;
            if(y!=y1)
                flag2=false;
        }
        if(!flag1&&!flag2)
            System.out.println("NO");
        else
            System.out.println("YES");
    }
}