#include<iostream>
#include<cstring>
#include<vector>
#include<set>
#include<algorithm>
using namespace std;
using LL = long long;

int main(){

#ifdef LOCAL
    freopen("data.in", "r", stdin);
    freopen("data.out", "w", stdout);
#endif

    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);

    int n, x, y;
    cin >> n >> x >> y;
    vector<int> pt(n + 1, -1);
    pt[0] = 0;
    int ans = 0;
    for(int i = 1; i <= n; i++){
        int l1, r1, l2, r2;
        cin >> l1 >> r1 >> l2 >> r2;
        for(int j = 0; j <= n; j++){
            if (x + j < l1 or x + j > r1 or pt[j] == -1) continue;
            int mn = max(0, l2 - y);
            int mx = min(n - j, r2 - y);
            if (pt[j] >= mn and pt[j] <= mx){
                ans = max(ans, j + ++pt[j]);
                if (j == 0){
                    pt[pt[j]] = 0;
                }
            }
        }
    }
    cout << ans << '\n';

}