#include <bits/stdc++.h>

const int N = 5e3 + 5;

int n, a, b, f[N][N], g[N][N];

int main () {
    std::cin >> n >> a >> b;
    f[0][0] = 1;
    for (int al, ar, bl, br, p = 1; p <= n; p++) {
        std::cin >> al >> ar >> bl >> br;
        for (int i = std::max(0, al - a); i <= std::min(p, ar - a); i++)
            for (int j = std::max(0, bl - b); j <= std::min(p, br - b); j++)
                g[i + 1][j] |= f[i][j], g[i][j + 1] |= f[i][j];
        for (int i = 0; i <= p; i++)
            for (int j = 0; j <= p; j++)
                f[i][j] |= g[i][j], g[i][j] = 0;
    }
    int ans = 0;
    for (int i = 0; i <= n; i++)
        for (int j = 0; j <= n; j++)
            ans = std::max(ans, f[i][j] * (i + j));
    std::cout << ans << "\n";
    return 0;
}