#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=2e9+1;
const ll INF=4e18;
const ll dy[8]={-1,0,1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
template <typename T> inline bool chmax(T &a, T b) {
  return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
  return ((a > b) ? (a = b, true) : (false));
}

struct SCC{//多重辺、自己辺ok
    int n,k=0;
    vector<vector<int>> g,rg;
    vector<vector<long long>> ret;
    vector<int> vs,cmp;
    vector<bool> used;
    SCC(int _n){
        n=_n;
        g=vector<vector<int>>(n);rg=g;
        cmp=vector<int>(n);used=vector<bool>(n);
    }
    void add_edge(int f, int t){
        g[f].push_back(t);rg[t].push_back(f);
    }
    int init(){
        rep(i,n)if(!used[i])dfs(i);
        used=vector<bool>(n,false);
        per(i,n){
            if(!used[vs[i]]){
                rdfs(vs[i],k);
                k++;
            }
        }
        return k;
    }
    vector<vector<ll>> build(){//自己辺はないが多重辺あり
        ret.resize(k);
        rep(i,n){
            for(auto to:g[i]){
                if(cmp[i]==cmp[to])continue;
                ret[cmp[i]].push_back(cmp[to]);
            }
        }
        return ret;
    }
    private:
    void dfs(int v){
        used[v]=true;
        rep(i,g[v].size()){
            if(!used[g[v][i]])dfs(g[v][i]);
        }
        vs.push_back(v);
    }
    void rdfs(int v, int k){
        used[v]=true;cmp[v]=k;
        rep(i,rg[v].size()){
            if(!used[rg[v][i]]){
                rdfs(rg[v][i],k);
            }
        }
    }
};

struct twoSAT{
    vector<bool> ans;
    twoSAT(int _n):n(_n),graph(2*_n),ans(_n){}
    void add_edge(int i,bool x,int j,bool y){//( i V j ),falseは否定
        if(!x)i+=n;if(!y)j+=n;
        graph.add_edge((i+n)%(2*n),j);
        graph.add_edge((j+n)%(2*n),i);
    }
    bool exe(){
        graph.init();
        rep(i,n){
            if(graph.cmp[i]==graph.cmp[i+n])return false;
            else if(graph.cmp[i]>graph.cmp[i+n])ans[i]=true;
            else ans[i]=false;
        }
        return true;
    }
    private:
    int n;SCC graph;
};

int main(){
  ll n;cin >> n;
  vpl x(n),y(n);
  rep(i,n){
    cin >> x[i].first >> x[i].second >> y[i].first >> y[i].second;
  }
  twoSAT ts(n);
  rep(i,n){
    rep(j,i){
      if(x[i]==x[j]){
        ts.add_edge(i,false,j,false);
      }
      if(x[i]==y[j]){
        ts.add_edge(i,false,j,true);
      }
      if(y[i]==x[j]){
        ts.add_edge(i,true,j,false);
      }
      if(y[i]==y[j]){
        ts.add_edge(i,true,j,true);
      }
    }
  }
  auto ans=ts.exe();
  if(ans)cout << "YES" << endl;
  else cout << "NO" << endl;
}