#include<bits/stdc++.h>
using namespace std;
#define inf 1000000000
#define INF 1000000000000000
#define ll long long
#define ull unsigned long long
#define M (int)(1e9+7)
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(a,n) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265
#define F first
#define S second
#define PB push_back
#define EB emplace_back
#define int ll
void init(){
  cin.tie(0);
  ios::sync_with_stdio(false);
}




template< typename T >
struct edge {
  int src, to;
  T cost;

  edge(int to, T cost) : src(-1), to(to), cost(cost) {}

  edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

  edge &operator=(const int &x) {
    to = x;
    return *this;
  }

  operator int() const { return to; }
};

template< typename T >
using Edges = vector< edge< T > >;
template< typename T >
using WG = vector< Edges< T > >;
using UG = vector< vector< int > >;
template< typename T >
using Matrix = vector< vector< T > >;


void f(int i,UG es,int k,vector<int> b){

  if(b[i]==0) b[i]=k;

  for(auto e:es[i]){
    if(b[e]==0){
      f(e,es,-k,b);
    }else if(b[i]==b[e]){
      cout<<"NO"<<endl;
      exit(1);
    }
  }

}


main(){
  int n;
  cin>>n;
  UG es(n);
  vector<P> v,w;

  rep(i,n){
    int a,b,c,d;
    cin>>a>>b>>c>>d;
    v.PB(P(a,b));
    w.PB(P(c,d));
  }

  rep(i,n){
    FOR(j,i+1,n){
      if(v[i]==v[j]||w[i]==w[j]||v[i]==w[j]||w[i]==v[j]){
        es[i].PB(j);
        es[j].PB(i);
      }
    }
  }

  vector<int> b(n,0);

  rep(i,n){
    f(i,es,1,b);
  }

  cout<<"YES"<<endl;


}