#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;
        int x[n];
        int y[n];
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
    
        cin >> x[a0] >> y[a0];
    }
    string Hor="Yes",Ver="Yes";
    int k=x[0],l=y[0];
    
  for(int i=1;i<n;++i){
      if(k!=x[i]){Ver="No";}
      if(l!=y[i]){Hor="No";}
      
      
      
  }
    
    
    
    if((Ver=="Yes"||Hor=="Yes")&&(Ver!=Hor)){cout<<"YES";}
    else{cout<<"NO";}
        return 0;
}