#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i=0;i<(n);i++)
#define rep2(i,a,b) for (int i=(a);i<(b);i++)
#define rrep(i,n) for (int i=(n)-1;i>=0;i--)
#define rrep2(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define all(a) (a).begin(),(a).end()
#define ifnot(x) if(not(x))
#define dump(x)  cerr << #x << " = " << (x) << endl;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

int N;
const int H = 100;
const int W = 100;
const int SIZE = H * W;

int deg[SIZE];  // V -> Deg
int comp[SIZE]; // V -> Comp
int edge[SIZE]; // Comp -> |E|
int vert[SIZE]; // Comp -> |V|

void solve() {
  rep(i, SIZE) {
    comp[i] = i;
    vert[i] = 1;
  }

  cin >> N;
  rep(i, N) {
    int r1, c1, r2, c2;
    cin >> r1 >> c1 >> r2 >> c2;
    r1--; c1--; r2--; c2--;
    int s = r1 + c1 * W;
    int t = r2 + c2 * W;

    deg[s]++; deg[t]++;
    int cmin = min(comp[s], comp[t]);
    int cmax = max(comp[s], comp[t]);
    if (cmin != cmax) {
      rep(v, SIZE) if(comp[v] == cmax) comp[v] = cmin;
      edge[cmin] += edge[cmax];
      vert[cmin] += vert[cmax];
    }
    edge[cmin]++;
  }
  set<int> comps;
  rep(i, SIZE) {
    if (deg[i]) {
      comps.insert(comp[i]);
    }
  }

  bool yes = true;
  for(auto c : comps) {
    fprintf(stderr, "component %d: V = %d, E = %d\n", c, vert[c], edge[c]);
    if(edge[c] > vert[c]) {
      yes = false; break;
    }
  }
  puts(yes?"YES":"NO");
}

int main() {
  solve();
  return 0;
}