#include <bits/stdc++.h>
using namespace std;

using int_ = int;
#define int long long

int_ main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr);

  int n; cin >> n;
  set<int> xs, ys;
  for (int i=0; i<n; ++i) {
    int x, y; cin >> x >> y;
    xs.insert(x);
    ys.insert(y);
  }
  cout << ((xs.size()==1 || ys.size()==1) ? "YES" : "NO") << '\n';
}

/*
 * Local variables:
 * compile-command:"g++ -D_GLIBCXX_DEBUG -g3 -ggdb3 -O0 -Wall -Wextra -std=c++14 a.cc -o a && for f in *.in; do echo \"--- $f -------------\"; ./a <$f; done"
 * end:
 */