#include <iostream>
#include <vector>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <array>

#define all(x) x.begin(), x.end()
#define forn(i, n) for(int i = 0; i < (n); ++i)
#define debug(x) std::cerr << "DEBUG: " << #x << " = " << (x) << std::endl

using namespace std;

int main() {
  // freopen("in.txt", "r", stdin);


  int n;
  cin >> n;
  vector<int> x(n), y(n);
  forn (i, n) {
    cin >> x[i] >> y[i];
  }

  if (*min_element(all(x)) == *max_element(all(x)) ||
      *min_element(all(y)) == *max_element(all(y))) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }


  return 0;
}