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

using namespace std;

void solveChallenge(vector<pair<int,int>> &points, int n){

  bool v=true;
  int x=points[0].first;
  for(int i=1;i<n;++i){
    if(points[i].first!=x){
      v=false;
      break;
    }
  }
  if(v){
    cout<<"YES"<<endl;
    return;
  }

  v=true;
  x=points[0].second;
  for(int i=1;i<n;++i){
    if(points[i].second!=x){
      v=false;
      break;
    }
  }
  if(v)
    cout<<"YES"<<endl;
  else
    cout<<"NO"<<endl;

}

void getInput(){
  int n;
  cin>>n;
  vector<pair<int,int>> points(n);
  for(int i=0;i<n;++i){
    pair<int,int> p;
    cin>>p.first>>p.second;
    points[i]=p;
  }
  solveChallenge(points,n);
}

int main(){
  getInput();
  return 0;
}