#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define all(x) begin(x), end(x)
#define sz(x) int((x).size())
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;

#ifdef LOCAL
auto operator<<(auto& o, auto x) -> decltype(x.first, o);
auto operator<<(auto& o, auto x) -> decltype(x.end(), o) {
  o << "{";
  for (int i = 0; auto y : x) o << ", " + !i++ * 2 << y;
  return o << "}";
}
auto operator<<(auto& o, auto x) -> decltype(x.first, o) {
  return o << "(" << x.first << ", " << x.second << ")";
}
void __print(auto... x) { ((cerr << x << " "), ...) << endl; }
#define debug(x...) __print("[" #x "]:", x)
#else
#define debug(...) 2137
#endif

constexpr int sz = 5010;
using B = bitset<sz + 1>;

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int n, a, b;
  cin >> n >> a >> b;

  vector<tuple<int, int, int, int>> v;

  for(int i = 0; i < n; i++) {
    int a0, a1, b0, b1;
    cin >> a0 >> a1 >> b0 >> b1;
    a0 -= a;
    a1 -= a;
    b0 -= b;
    b1 -= b;
    if(a0 > sz || b0 > sz)
      continue;
    a1 = min(a1, sz);
    b1 = min(b1, sz);
    v.emplace_back(a0, a1, b0, b1);
  }

  vector<B> dp(sz + 1, B());
  auto dp2 = dp;
  dp[0][0] = 1;

  for(auto [a0, a1, b0, b1] : v) {
    for(auto &i : dp2)
      i.reset();
    B good;
    good.reset();
    for(int i = b0; i <= b1; i++)
      good[i] = 1;
    for(int i = a0; i <= min(a1 + 1, sz); i++) {
      if(i)  {
        debug(i, i - 1);
        dp2[i] |= dp[i - 1] & good;
      }
      if(i <= a1)
        dp2[i] |= (dp[i] & good) << 1;
    }
    swap(dp, dp2);
  }

  int mx = 0;

  for(int i = 0; i <= sz; i++) {
    for(int j = 0; j <= sz; j++) {
      if(dp[i][j])
        mx = max(mx, i + j);
    }
  }

  cout << mx << endl;
}