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();
        String vOrH = "NO";
        int xC = 1, yC = 1, pX = 0, pY = 0;
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            if(a0 >= 1){
                if(pX == x) xC += 1;
                if(pY == y) yC += 1;
            }
            pX = x;
            pY = y;
        }
        if(xC == n || yC == n) vOrH = "YES";
        System.out.println(vOrH);
    }
}