#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
// #pragma GCC optimize("O2")
// #pragma GCC optimize("unroll-loops")
#define pb push_back
#define del pop_back
#define ll long long
#define double long double
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pli pair<ll, int>
#define deriva_e_iguala_a return
#define fcin ios_base::sync_with_stdio(false)
#define rep(i, a, b) for(int i = a; i < b; i++)
#define all(v) v.begin(), v.end()
#define print(vec, a, b) {for(int f = a; f < b; f++)cout << vec[f] << ' '; cout << endl;}
#define printr(vec) {for(auto f: vec) cout << f << ' '; cout << endl;}
#define endl '\n'
#define f first
#define s second


using namespace std;
// using namespace __gnu_pbds;

 
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());


template<class T> using ordered_set = __gnu_pbds::tree<T, __gnu_pbds::null_type, std::less<T>, __gnu_pbds::rb_tree_tag, __gnu_pbds::tree_order_statistics_node_update>;
//<T> -> set, pair<T, int> -> multiset
template<class T> using min_priority_queue = std::priority_queue<T, std::vector<T>, std::greater<T>>;

template<typename T, typename U>
pair<T, U> operator + (pair<T, U>& a, pair<T, U>& b){ return make_pair(a.first + b.first, a.second + b.second); }
template<typename T, typename U>
pair<T, U> operator += (pair<T, U>& a, pair<T, U> b){ a = a+b; return a; }
template<typename T, typename U>
istream& operator >> (istream& in, pair<T, U>& a){ in >> a.first >> a.second; return in; }
template<typename T, typename U>
ostream& operator << (ostream& out, const pair<T, U>& a){ out << a.first << ' ' << a.second; return out; }
template<typename T>
bool ckmin(T& a, T b){ return a > b ? a = b, true : false; }
template<typename T>
bool ckmax(T& a, T b){ return a < b ? a = b, true : false; }


const int IINF = 2e9 + 1, MOD = 998244353, MOD2 = 1e9 + 7, root = 48;
const ll INF = 1e18;
const double PI = acos(-1), eps = 1e-9;
const int dx[] = {0, 1, 0, -1}, dy[] = {-1, 0, 1, 0}; // LDRU


const int N = 5e3 + 3;


set<int, greater<int>> lazy[N];
int vis[N][N];


int main(){
    fcin;
    cin.tie(0);
    // freopen("in.txt", "r", stdin);
    // freopen("out.txt", "w", stdout);
    int t = 1;
    // cin >> t;
    while(t--){
        int n, a, b;
        cin >> n >> a >> b;
        vector<pii> xx(n), yy(n);
        for(int i = 0; i < n; ++i){
            cin >> xx[i].f >> xx[i].s >> yy[i].f >> yy[i].s;
            xx[i] += mp(-a, -a);
            yy[i] += mp(-b, -b);
        }
        vis[0][0] = 1;
        lazy[0].insert(0);
        for(int i = 0; i < n; ++i){
            lazy[i].insert(-1);
        }
        set<int> hmm = {1, 2, 3, 4, 5, 6, 7};
        for(int i = 0; i < n; ++i){
            auto [xl, xr] = xx[i];
            auto [yl, yr] = yy[i];
            int lim = min(xr, n-1);
            for(int j = xl; j <= lim; ++j){
                for(auto it = lazy[j].lower_bound(yr); *it >= yl; it = lazy[j].erase(it)){
                    int k = *it;
                    if(!vis[j+1][k]){
                        vis[j+1][k] = 1;
                        lazy[j+1].insert(k);
                    }
                    if(!vis[j][k+1]){
                        vis[j][k+1] = 1;
                        lazy[j].insert(k+1);
                    }
                }
            }
        }
        int ans = 0;
        for(int i = 0; i <= n; ++i){
            for(int j = 0; j <= n; ++j){
                if(vis[i][j]){
                    ans = max(ans, i+j);
                }
            }
        }
        cout << ans << endl;
    }
}