/* -*- coding: utf-8 -*-
 *
 * 483.cc: No.483 マッチ並べ - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100;
const int MAX_GN = MAX_N * 2;
const int MAX_X = 100;
const int MAX_Y = 100;

/* typedef */

typedef vector<int> vi;
typedef queue<int> qi;
typedef pair<int,int> pii;

/* global variables */

pii es[MAX_N];
int gn = 0, gids[MAX_Y][MAX_X];
vi nbrs[MAX_GN];
int used[MAX_GN];

/* subroutines */

inline int readgid(int y, int x) {
  return (gids[y][x] < 0) ? (gids[y][x] = gn++) : gids[y][x];
}

/* main */

int main() {
  memset(gids, -1, sizeof(gids));

  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int y0, x0, y1, x1;
    cin >> y0 >> x0 >> y1 >> x1;
    y0--, x0--, y1--, x1--;
    int u = readgid(y0, x0);
    int v = readgid(y1, x1);
    nbrs[u].push_back(v);
    nbrs[v].push_back(u);
    es[i] = pii(u, v);
  }
  //printf("gn=%d\n", gn);

  int cid = 0;
  for (int st = 0; st < gn; st++) {
    if (used[st] > 0) continue;

    qi q;
    q.push(st);
    used[st] = ++cid;
    int cn = 1;

    while (! q.empty()) {
      int u = q.front(); q.pop();
      vi &nbru = nbrs[u];
      for (vi::iterator vit = nbru.begin(); vit != nbru.end(); vit++) {
	int &v = *vit;
	if (! used[v]) {
	  q.push(v);
	  used[v] = cid;
	  cn++;
	}
      }
    }

    int en = 0;
    for (int i = 0; i < n; i++)
      if (used[es[i].first] == cid) en++;
    //printf("cn=%d, en=%d\n", cn, en);

    if (en > cn) {
      puts("NO");
      return 0;
    }
  }

  puts("YES");
  return 0;
}