#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define PII pair<int,int>
#define pb push_back
#define mk make_pair


int main(){
    
    
   
    	int n;cin>>n;
    	vector<PII > A;


    	int temp,flag;
    	for(int i=0;i<n;i++){
            int x,y;
            cin>>x>>y;
            A.push_back(make_pair(x,y));
    	}
        
        temp=0;
            for(int i=1;i<n;i++){
                if(A[i].first!=A[0].first){
                    temp=1;break;}
            }
            if(temp==0){
                cout<<"YES\n";
                return 0;}
            
        
        temp=0;
            for(int i=1;i<n;i++){
                if(A[i].second!=A[0].second){
                    temp=1;break;}
            }
            if(temp==0)
                cout<<"YES\n";
            else
                cout<<"NO\n";
        

    

    return 0;
}