#include <iostream>
#include <algorithm>
#include <bitset>

typedef long long ll;
typedef double lf;

// #define DEBUG 1
struct IO
{
    #define MAXSIZE (1 << 20)
    #define isdigit(x) (x >= '0' && x <= '9')
    char buf[MAXSIZE], *p1, *p2;
    char pbuf[MAXSIZE], *pp;
    #if DEBUG
    #else
    IO() : p1(buf), p2(buf), pp(pbuf) {}
    ~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
    #endif
    #define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
    #define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')

    template <typename T>
    void Read(T &x)
    {
        #if DEBUG
        std::cin >> x;
        #else
        bool sign = 0; char ch = gc(); x = 0;
        for (; !isdigit(ch); ch = gc())
            if (ch == '-') sign = 1;
        for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
        if (sign) x = -x;
        #endif
    }
    void Read(char *s)
    {
        #if DEBUG
        std::cin >> s;
        #else
        char ch = gc();
        for (; blank(ch); ch = gc());
        for (; !blank(ch); ch = gc()) *s++ = ch;
        *s = 0;
        #endif
    }
    void Read(char &c) {for (c = gc(); blank(c); c = gc());}

    void Push(const char &c)
    {
        #if DEBUG
        putchar(c);
        #else
        if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
        *pp++ = c;
        #endif
    }
    template <typename T>
    void Write(T x)
    {
        if (x < 0) x = -x, Push('-');
        static T sta[35];
        int top = 0;
        do sta[top++] = x % 10, x /= 10; while (x);
        while (top) Push(sta[--top] ^ 48);
    }
    template <typename T>
    void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)

using namespace std;

const int MAXN = 5005;

int n, A, B;
int al[MAXN], ar[MAXN], bl[MAXN], br[MAXN];

bitset <MAXN> pre[MAXN], suf[MAXN];
bitset <MAXN> f[2][MAXN], g;

int main()
{
    // freopen("M.in", "r", stdin);
    // freopen("M.out", "w", stdout);
    #if DEBUG
    #else
    ios::sync_with_stdio(0), cin.tie(0);
    #endif
    Read(n), Read(A), Read(B);
    int _n = 0;
    for (int i = 1, x1, y1, x2, y2; i <= n; i++)
    {
        Read(x1), Read(y1), Read(x2), Read(y2);
        if (y1 < A || y2 < B) continue;
        _n++;
        al[_n] = max(0, x1 - A), ar[_n] = y1 - A;
        bl[_n] = max(0, x2 - B), br[_n] = y2 - A;
    }
    n = _n;
    for (int i = 1; i <= n; i++) ar[i] = min(ar[i], n), br[i] = min(br[i], n);
    pre[0].set(0);
    for (int i = 1; i <= n; i++) pre[i] = pre[i - 1], pre[i].set(i);
    suf[n].set(n);
    for (int i = n - 1; i >= 0; i--) suf[i] = suf[i + 1], suf[i].set(i);
    // cout << n << "\n";
    // for (int i = 1; i <= n; i++) cout << al[i] << ' ' << ar[i] << ' ' << bl[i] << ' ' << br[i] << "\n";

    int p = 0;
    f[0][0].set(0);
    for (int i = 1; i <= n; i++)
    {
        for (int j = 0; j < i; j++) f[p ^ 1][j] = f[p][j];
        for (int j = al[i]; j < i && j <= ar[i]; j++)
        {
            if (f[p][j].none()) continue;
            g = f[p][j], g &= pre[br[i]], g &= suf[bl[i]];
            if (g.none()) continue;
            f[p ^ 1][j + 1] |= g, f[p ^ 1][j] |= g << 1;
        }
        p ^= 1;
        // for (int j = 0; j <= i; j++, cout << '\n')
        //     for (int k = 0; k <= i; k++)
        //     {
        //         cout << f[p][j][k] << ' ';
        //     }
    }
    int ans = 0;
    for (int i = 0; i <= n; i++)
        for (int j = 0; i + j <= n; j++)
            if (f[p][i].test(j)) ans = max(ans, i + j);
    cout << ans << '\n';
    return 0;
}