#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n,tx=0,ty=0;
    
    
    cin>>n;
   
   
    int x[15],y[15];
    for(int i=0;i<n;i++)
        {
        cin>>x[i]>>y[i];     
    }
    for(int i=0;i<n-1;i++)
        {
        if(x[i]!=x[i+1])
        {    tx=-1;
        break;
        }
        
        
    }
     for(int i=0;i<n-1;i++)
        {
        if(y[i]!=y[i+1])
        {    ty=-1;
        break;
        }
        
        
    }
    
    if(tx==-1&&ty!=-1)
        cout<<"YES\n";
    else
        {
        if(ty==-1&&tx!=-1)
        cout<<"YES\n";
        else
            cout<<"NO\n";
    }
    
   
   
    
    return 0;
}