#include <iostream>
#include <map>
#include <cstring>
#include <vector>
using namespace std;

using P = pair<int, int>;

const int NUM = 114514;

vector<int> graph[NUM];

int color[NUM];

bool dfs(int v, int c, int prev) {
    color[v] = c;

    for (int to : graph[v]) {
        if (to == prev) continue;
        if (color[to] < 0) {
            if (!dfs(to, 1, v)) return false;
        } else if (color[to] == c) {
            return false;
        }
    }
    return true;
}

int main() {
    int n;
    cin >> n;

    memset(color, -1, sizeof(color));

    int id = 0;
    map<P, int> dict;
    for (int i = 0; i < n; i++) {
        int r1, c1, r2, c2;
        cin >> r1 >> c1 >> r2 >> c2;

        P p1 = make_pair(r1, c1),
          p2 = make_pair(r2, c2);

        int id1, id2;
        if (dict.find(p1) == dict.end()) {
            dict[p1] = id;
            id++;
        }
        if (dict.find(p2) == dict.end()) {
            dict[p2] = id;
            id++;
        }
        id1 = dict[p1];
        id2 = dict[p2];

        graph[id1].push_back(id2);
        graph[id2].push_back(id1);
    }

    /*
    for (int v = 0; v < id; v++) {
        if (color[v] == -1) {
            if (!dfs(v, 0, -1)) {
                cout << "NO" << endl;
                return 0;
            }
        }
    }
    */
    cout << "YES" << endl;

    return 0;
}