#include <bits/stdc++.h>
using namespace std;
void mohammed() {
  ios::sync_with_stdio(0);
  ios_base::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
}
int main() {
  mohammed();
  int n, x, y;
  cin >> n;
  map<int, int> mp;
  map<int, int>::iterator it;
  for (int i = 0; i < n; i++) {
    cin >> x >> y;
    mp[x]++;
    mp[y + 1]--;
  }
  x = 0;
  for (it = mp.begin(); it != mp.end(); it++) {
    it->second += x;
    if (it->second > 2) {
      cout << "NO";
      return 0;
    }
    x = it->second;
  }
  cout << "YES";
  return 0;
}
