#ifdef __GNUC__
#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#endif

#define _USE_MATH_DEFINES

#include <iostream>
#include <iomanip>
#include <stdio.h>

#include <sstream>
#include <algorithm>
#include <cmath>

#include <string>
#include <cstring>
#include <vector>
#include <valarray>
//#include <array>//x C++ (G++ 4.6.4)

#include <queue>
#include <complex>
#include <set>
#include <map>
#include <stack>
#include <list>

#include <cassert>//assert();
#include <fstream>
/////////
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)

/////////
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
#define PII pair<int,int>
/////////
using namespace::std;

// 最大公約数
template<class T>
inline T gcd(T a, T b){return b == 0 ? a : gcd(b, a % b);}
// 最小公倍数
template<class T>
inline T lcm(T a, T b){return a * b / gcd(a, b);}
////////////////////////////////
class UnionFind{
public:
	int cNum;//要素数
	vector<int> parent;
	UnionFind(int n){
		cNum = n;
		parent = vector<int>(n);
		for(int i=0;i<n;++i){parent[i] = i;}
	}
	int find(int x){
		if( parent[x] == x ){return x;}
		return parent[x] = find( parent[x] );
	}
	bool same(int x,int y){return find(x) == find(y);}
	void add(int x,int y){//union
		x = find(x);
		y = find(y);
		if( x==y )return;
		parent[x] = y;
	}
};

inline void solve(){
	int N;
	cin >> N;
	int R,C,RR,CC;
	vector< vector<int> > G(10000);
	vector< bool > used(10001,false);
	set<int> nodeSet;
	UnionFind uf(10001);
	int A,B;
	for(int i=0;i<N;++i){
		cin >> R >> C >> RR >> CC;
		--R;--C;--RR;--CC;
		//[0,99]100個
		A = R+C*100;
		B = RR+CC*100;
		G[ A ].push_back(B);
		G[ B ].push_back(A);
		nodeSet.insert(A);
		nodeSet.insert(B);
	}
	set<int>::iterator setPos,setEnd;
	setPos = nodeSet.begin();
	setEnd = nodeSet.end();
	vector<int>::iterator itr,end;
	int nodeNo;
	queue<int> queNodeNo;
	int closeCount;
	for(;setPos != setEnd;++setPos){
		nodeNo = *setPos;
		if( used[nodeNo] ) continue;
		closeCount = 0;//1許容、２ダメ
		queNodeNo.push(nodeNo);
		while( !queNodeNo.empty() ){
			nodeNo = queNodeNo.front();queNodeNo.pop();
			used[nodeNo] = true;
			itr = G[nodeNo].begin();
			end = G[nodeNo].end();
			A = nodeNo;
			for(;itr != end;++itr){
				B = *itr;
				if( used[B] == true ) continue;
				if( uf.same(A,B) ){
					++closeCount;
					if( closeCount >= 2 ){
						cout << "NO" << endl;
						return;
					}
				}
				uf.add(A,B);
				queNodeNo.push(B);
			}
		}
	}

	cout << "YES" << endl;
}

signed main(void){
	std::cin.tie(0);
	std::ios::sync_with_stdio(false);
	//std::cout << std::fixed;//小数を10進数表示
	//cout << setprecision(16);//小数をいっぱい表示する。16?

	solve();
}