#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)



template<int um> class UF { // from kmjp
public:
	vector<int> par;
	UF() { par = vector<int>(um, 0); rep(i, 0, um) par[i] = i; }
	int operator[](int x) { return par[x] == x ? x : par[x] = operator[](par[x]); }
	void operator()(int x, int y)
	{
		x = operator[](x); y = operator[](y);
		if (x != y) par[x] = y;
	}
};
int N;
set<int> vec;
vector<int> E[20101];
//-----------------------------------------------------------------
UF<20101> uf;
map<int, vector<int>> m;
string sol() {
	for (int v : vec) for (int to : E[v]) uf(v, to);
	for (int v : vec) m[uf[v]].push_back(v);

	bool ans = true;
	for (auto p : m) {
		auto vs = p.second;

		int e = 0;
		for (int i : vs) e += E[i].size();
		e /= 2;

		int n = vs.size();

		if (n + 1 <= e) ans = false;
	}

	if (ans)
		return "YES";
	else
		return "NO";
}
//-----------------------------------------------------------------
int main() {
	cin >> N;
	rep(i, 0, N) {
		int r0, c0, r1, c1;
		scanf("%d %d %d %d", &r0, &c0, &r1, &c1);
		r0--; c0--; r1--; c1--;

		int a = r0 * 150 + c0;
		int b = r1 * 150 + c1;
		vec.insert(a);
		vec.insert(b);
		E[a].push_back(b);
		E[b].push_back(a);
	}
	cout << sol() << endl;
}