#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define FOR(i, a, b) for (int i = (a); i < int(b); ++i)
#define RFOR(i, a, b) for (int i = (b) - 1; i >= int(a); --i)
#define rep(i, n) FOR(i, 0, n)
#define rep1(i, n) FOR(i, 1, int(n) + 1)
#define rrep(i, n) RFOR(i, 0, n)
#define rrep1(i, n) RFOR(i, 1, int(n) + 1)
#define all(c) begin(c), end(c)
template<typename T> void __dump__(const T &first){ std::cerr << first << std::endl; }
template<typename First, typename... Rest>
void __dump__(const First& first, const Rest&... rest) { std::cerr << first << ", "; __dump__(rest...); }
#define dump(...) { std::cerr << __LINE__ << ":\t" #__VA_ARGS__ " = "; __dump__(__VA_ARGS__); }

const int R = 120;
const int C = 120;
const int N = R*C;

class bipartite_matching {
public:
    int n;
    vector<vector<int>> g;
    vector<int> match;

    bipartite_matching(int n_) : n(n_), g(n_), match(n_), used(n_) {}

    void add_edge(int u, int v) {
        g[u].push_back(v);
        g[v].push_back(u);
    }

    int maximum_matching(void) {
        int res = 0;
        fill(begin(match), end(match), -1);
        for (int v = 0; v < n; ++v) {
            if (match[v] == -1) {
                fill(begin(used), end(used), false);
                if (dfs(v)) res++;
            }
        }
        return res;
    }

private:
    vector<int> used;
    bool dfs(int v) {
        used[v] = true;
        for (int u : g[v]) {
            int w = match[u];
            if (w == -1 || (!used[w] && dfs(w))) {
                match[v] = u;
                match[u] = v;
                return true;
            }
        }
        return false;
    }
};

int enc(int r, int c){
    return r*C + c;
}

int main(){
    int n;
    while(cin >> n){
        bipartite_matching bm(N + 100);
        rep(i, n){
            int r, c, rr, cc;
            cin >> r >> c >> rr >> cc;
            --r, --c, --rr, --cc;
            int x = enc(r, c), y = enc(rr, cc);
            bm.add_edge(i, x + 100);
            bm.add_edge(i, y + 100);
        }
        int f = bm.maximum_matching();
        dump(f);
        puts(f == n ? "YES" : "NO");
    }
}