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 vx[] = new int[n], vy[] = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            
            vx[a0] = x;
            vy[a0] = y;
        }
        String ris = "YES";
        boolean x = true, y = true;
        for(int a0 = 1; a0 < n && (x || y); a0++){
            if(vx[a0] != vx[a0 - 1])
                x = false;
            if(vy[a0] != vy[a0 - 1])
                y = false;
        }
        
        if(!x && !y)
            ris = "NO";
        
        System.out.println(ris);
    }
}