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();
        float[] m=new float[10];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            if(x==0 )
                m[a0]=-999;
            else if(y==0)
                m[a0]=0;
            else
                m[a0]=-1;
            
                
            
            
            
        }
        boolean flag=true;
        for(int i=0;i<n-1;i++)
            if(m[i]!=m[i+1])
            {
            flag=false;
            break;
        }
        if(flag==true)
            System.out.println("YES");
        else
            System.out.println("NO");
        
        
    }
}