//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using namespace std;
using ll = int64_t;
using ld = long double;
using P = pair<int, int>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T> >;
const int INF = 100010001;
const ll LINF = (ll)INF*INF*10;
template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true);}
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true);}
template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}

const int N = 10000;

struct UnionFind {
  vector<int> par; // 親を指すvector,-par[親]は木のサイズ
  UnionFind(int n):par(n, -1) {} // uniteで親を埋め込んでいく必要あり
  int root(int x) { // 親をたどる&データの整理
    if(par[x] < 0) return x;
    return par[x] = root(par[x]);
  }
  bool unite(int x, int y) { // データの結合
    x = root(x);
    y = root(y);
    if(x == y) return false;
    if(par[x] > par[y]) swap(x, y);
    par[x] += par[y];
    par[y] = x;
    return true;
  }
  bool same(int x, int y) {return root(x) == root(y);} // 所属判定
  int size(int x) {return -par[root(x)];} // 木のサイズ
};

//head

inline int num(int i, int j) {return i*100 + j;}

int n;
vi G[N];
bitset<N> bits, B;
bool able = true;
UnionFind uft(N);
vi dame;

inline void add(int i, int j) {
  G[i].emplace_back(j);
  G[j].emplace_back(i);
  uft.unite(i, j);
}

bool dfs(int i, int j, int r) {
  //cout << i << ' ' << j << ' ' << r << endl;
  for(int nw:G[i]) {
    if(nw == j) continue;
    if(i == r and find(all(dame), nw) != dame.end()) continue;
    if(bits.test(nw)) {
      //cout << r << ' ' << nw << ' ' << i << ' ' << j << ' ' << 1 << endl;
      return false;
    }
    bits.set(nw);
    if(nw != r) {
      if(!dfs(nw, i, r)) {
        //cout << r << ' ' << nw << ' ' << 2 << endl;
        return false;
      }
    }
    else {
      dame.emplace_back(i);
    }
  }
  return true;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  rep(i, n) {
    int r0, c0, r1, c1;
    cin >> r0 >> c0 >> r1 >> c1;
    c0 -= 39; c1 -= 39;
    r0++; r1++;
    add(num(r0-1, c0-1), num(r1-1, c1-1));
  }

  rep(i, N) {
    if(!B.test(uft.root(i))) {
      bits = 0;
      dame.clear();
      if(dfs(i, -1, i)) {
        B.set(uft.root(i));
      }
    }
  }
  rep(i, N) if(i == uft.root(i)) {
    if(!B.test(i)) able = false;
  }

  cout << (able?"YES":"NO") << endl;
}