#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;


int main(){
    int n;
    cin >> n;
 
    bool no = true,yes = true;
    
    int xx = 0,yy = 0;
    
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
       
        if(a0 == 0) {xx = x;yy = y;}
        
        if(a0>0 && xx!=x)
                 no = false;
        if(a0>0 && yy!=y)
        	     yes = false;
      
        }
   
      if(no || yes) cout<<"YES"<<endl;
        else cout<<"NO"<<endl;
    
    return 0;
}