// MagicDark
#include <bits/stdc++.h>
#define mid ((l + r) >> 1)
#define ls num << 1
#define rs ls | 1
#define li ls, l, mid
#define ri rs, mid + 1, r
#define debug cerr << "\033[32m[" << __LINE__ << "]\033[0m "
#define SZ(x) ((int) x.size() - 1)
#define all(x) x.begin(), x.end()
#define ms(x, y) memset(x, y, sizeof x)
#define F(i, x, y) for (int i = (x); i <= (y); i++)
#define DF(i, x, y) for (int i = (x); i >= (y); i--)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
template <typename T> T& chkmax(T& x, T y) {return x = max(x, y);}
template <typename T> T& chkmin(T& x, T y) {return x = min(x, y);}
template <typename T> T& read(T &x) {
	x = 0; int f = 1; char c = getchar();
	for (; !isdigit(c); c = getchar()) if (c == '-') f = -f;
	for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
	return x *= f;
}
const int N = 5010, inf = 1e9;
int n, a, b, la[N], ra[N], lb[N], rb[N], f[N][N];
// pair <int, int> 
vector <int> seg[N << 2];
int info[N << 2];
void pushup(int num) {
	info[num] = min(info[ls], info[rs]);
	if (seg[num].size()) chkmin(info[num], seg[num].back());
}
void change(int num, int l, int r, int L, int R, int x) {
	if (L <= l && r <= R) {
		seg[num].push_back(x);
		return;
	}
	if (mid >= L) change(li, L, R, x);
	if (mid < R) change(ri, L, R, x);
	pushup(num);
}
void del(int num, int l, int r, int L, int R) {
	if (L <= l && r <= R) {
		seg[num].pop_back();
		pushup(num);
		return;
	}
	if (mid >= L) del(li, L, R);
	if (mid < R) del(ri, L, R);
	pushup(num);
}
int query(int num, int l, int r, int x) {
	int ans = seg[num].size() ? seg[num].back() : inf;
	if (l == r) return ans;
	if (mid >= x) return min(ans, query(li, x));
	return min(ans, query(ri, x));
}
// int query(int num, int l, int r, int L, int R) {
// 	if (L <= l && r <= R) return info[num];
// 	int ans = seg[num].size() ? seg[num].back() : inf;
// 	if (mid >= L) chkmin(ans, query(li, L, R));
// 	if (mid < R) chkmin(ans, query(ri, L, R));
// 	return ans;
// }
bool vis[N];
vector <int> v1[N], v2[N];
signed main() {
	ms(info, 0x3f);
	read(n), read(a), read(b);
	F(i, 1, n) {
		read(la[i]), read(ra[i]), read(lb[i]), read(rb[i]);
		la[i] = max(0, la[i] - a);
		ra[i] = min(i, ra[i] - a);
		lb[i] = max(0, ra[i] - b);
		rb[i] = min(i, rb[i] - b);
		if (la[i] > ra[i] || lb[i] > rb[i]) {
			i--;
			n--;
			continue;
		}
	}
	ms(f, 0x3f);
	f[0][0] = 0;
	F(i, 0, n) {
		F(j, 1, n * 4) {
			seg[j].clear();
			info[j] = inf;
		}
		F(j, 0, n) v1[j].clear(), v2[j].clear();
		// trans to j + 1
		DF(j, n, 1) {
			if (la[j] <= i && i <= ra[j]) change(1, 0, n, la[j], rb[j], j);
			if (la[j] <= i + 1 && i + 1 <= ra[j]) v1[la[j]].push_back(j), v2[ra[j] + 1].push_back(j);
		}
		ms(vis, false);
		priority_queue <pair <int, int>, vector <pair <int, int>>, greater <pair <int, int>>> q;
		F(j, 0, n) q.emplace(make_pair(f[i][j], j));
		int pos = 1;
		while (q.size()) {
			auto [x, y] = q.top(); q.pop();
			if (vis[y]) continue;
			if (x >= n) break;
			vis[y] = true;
			while (pos <= x) {
				if (la[pos] <= i && i <= ra[pos]) del(1, 0, n, la[pos], rb[pos]);
				pos++;
			}
			int val = query(1, 1, n, y + 1);
			if (val < f[i][y + 1]) q.emplace(f[i][y + 1] = val, y + 1);
		}
		set <int> s;
		F(j, 0, n) {
			for (int k: v1[j]) s.insert(k);
			for (int k: v2[j]) s.erase(k);
			auto it = s.upper_bound(f[i][j]);
			if (it != s.end()) chkmin(f[i + 1][j], * it);
		}
		// F(j, 0, n) {
		// 	if (!i && !j) f[i][j] = 0;
		// 	if (f[i][j] < n) {
		// 	}
		// }
	}
	int ans = 0;
	F(i, 0, n)
		F(j, 0, n)
			if (f[i][j] <= n) chkmax(ans, i + j);
	cout << ans;
	return 0;
}
/* why?
*/