#include <bits/stdc++.h>

using namespace std;

const int N = 5010;

int n, x, y, lx[N], rx[N], ly[N], ry[N], ans;
bitset<N> dp[2][N], Empty;

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> n >> x >> y;
    for (int i = 1; i <= n; i++) {
        cin >> lx[i] >> rx[i] >> ly[i] >> ry[i];
    }
    dp[0][0][0] = 1;
    for (int i = 1; i <= n; i++) {
        int k = i & 1;
        for (int j = 0; j <= n; j++) {
            dp[k][j] = dp[k ^ 1][j];
            if (lx[i] <= x + j && x + j <= rx[i]) {
                dp[k][j] |= (dp[k ^ 1][j] << 1) | (dp[k ^ 1][j - 1]);
            }
        }

        if (0 <= ly[i] - y && ly[i] - y <= n && 0 <= ry[i] - y && ry[i] - y <= n) {
            int l = ly[i] - y, r = ry[i] - y;
            for (int j = 0; j <= n; j++) {
                dp[k][j] = (dp[k][j] >> l) << l;
                dp[k][j] = (dp[k][j] << (n - r)) >> (n - r);
                dp[k ^ 1][j] = Empty;
            }
        }
    }

    for (int i = 0; i <= n; i++) {
        for (int j = 0; j <= n; j++) {
            if (dp[n & 1][i][j]) ans = max(ans, i + j);
        }
    }
    cout << ans;
    return 0;
}