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


int main() {
   int n;
  
    cin>>n;
      int x[11];
    int y[11];
    int checkx=0,checky=0;
    for(int i=0;i<n;i++){
        cin>>x[i]>>y[i];
        if(n!=1){
        if(x[i]==x[i-1] && i!=0 && checkx!=-1){checkx=1;}else if(x[i]!=x[i-1] && i!=0){checkx=-1;}
       if(y[i]==y[i-1] && i!=0 && checky!=-1){checky=1;}else if(y[i]!=y[i-1] && i!=0){checky=-1;} 
        }else if(n==1){checkx=1; checky=1;}
        
    }
    if(checkx==1 || checky==1){cout<<"YES";}else {cout<<"NO";}
    return 0;
}