#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline string toString(T a) {
  ostringstream os("");
  os << a;
  return os.str();
}
template <typename T>
inline long long toLong(T a) {
  long long res;
  istringstream os(a);
  os >> res;
  return res;
}
template <typename T>
inline T SQ(T a) {
  return a * a;
}
template <typename T>
inline T gcd(T a, T b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
template <typename T>
inline unsigned long long bigmod(T a, T b, T m) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return S(bigmod(a, b / 2, m)) % m;
  else
    return (a % m * bigmod(a, b - 1, m)) % m;
}
template <typename T>
inline vector<string> parse(T str) {
  vector<string> res;
  string s;
  istringstream os(str);
  while (os >> s) res.push_back(s);
  return res;
}
template <typename T>
inline unsigned long long dist(T A, T B) {
  unsigned long long res =
      (A.x - B.x) * (A.x - B.x) + (A.y - B.y) * (A.y - B.y);
  return res;
}
template <typename T>
inline double cosAngle(T a, T b, T c) {
  double res = a * a + b * b - c * c;
  res = res / (2 * a * b);
  res = acos(res);
  return res;
}
template <typename T>
inline T power(T base, int po) {
  T res = 1;
  if (base == 0) return 0;
  for (int i = (0); i < (po); i++) res *= base;
  return res;
}
template <typename T>
inline bool isOn(T mask, T pos) {
  return mask & (1 << pos);
}
template <typename T>
inline int Off(T mask, T pos) {
  return mask ^ (1 << pos);
}
template <typename T>
inline int On(T mask, T pos) {
  return mask | (1 << pos);
}
vector<int> v;
vector<pair<int, int> > A, B;
int main() {
  int i, j, k;
  int x, y, xx, yy;
  int lx, ly, hx, hy;
  lx = 1000000;
  ly = lx;
  hx = 0;
  hy = 0;
  string str;
  int n;
  v.clear();
  cin >> n;
  long long tot = 0;
  for (int i = (0); i < (n); i++) {
    cin >> x >> y;
    pair<int, int> p = make_pair(x, y);
    if (lx > x) lx = x;
    if (ly > y) ly = y;
    cin >> xx >> yy;
    if (hx < xx) hx = xx;
    if (hy < yy) hy = yy;
    tot += (xx - x) * (yy - y);
  }
  long long res = 0;
  res = (hx - lx) * (hy - ly);
  if (res == tot && (hx - lx == hy - ly))
    puts("YES");
  else
    puts("NO");
  return 0;
}
