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#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <fstream>
#include <sstream>
#include <set>
#include <map>
#include <vector>
#include <list>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <string>
#include <queue>
#include <bitset>		//UWAGA - w czasie kompilacji musi byc znany rozmiar wektora - nie mozna go zmienic
#include <cassert>
#include <iomanip>		//do setprecision
#include <ctime>
#include <complex>
#include <chrono>
#include<unordered_map>
using namespace std;

#define FOR(i,b,e) for(int i=(b);i<(e);++i)
#define FORQ(i,b,e) for(int i=(b);i<=(e);++i)
#define FORD(i,b,e) for(int i=(b)-1;i>=(e);--i)
#define REP(x, n) for(int x = 0; x < (n); ++x)
#define ALL(u) (u).begin(),(u).end()

#define ST first
#define ND second
#define PB push_back
#define MP make_pair
#define LL long long
#define ULL unsigned LL
#define LD long double

typedef pair<int, int> PII;

const double pi = 3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342;

const int MR = 5e5 + 10;

pair<PII, PII> t[MR];
vector<pair<PII, PII>> states[MR];

pair<PII, PII> intersect(const pair<PII, PII> &p1, const pair<PII, PII> &p2)
{
	return MP(MP(max(p1.first.first, p2.first.first), max(p1.first.second, p2.first.second)), MP(min(p1.second.first, p2.second.first), min(p1.second.second, p2.second.second)));
}

LL makeMove(int pos, const vector<pair<PII, PII>> &V)
{
	LL res = 0;
	states[pos + 1].clear();
	for (const auto &p1 : states[pos])for (const auto &p2 : V)
	{
		auto p = intersect(p1, p2);
		LL a = (p.second.first - p.first.first)*(LL)(p.second.second - p.first.second);
		if (a <= 0 || p.first.first > p.second.first || p.first.second > p.second.second)
			continue;
		states[pos + 1].push_back(p);
		res += a;
	}

	return res;
}

int X, Y, n;
LL best;
void dfs(int pos)
{
	// wykonaj 4 ruchy

	// prostokat
	{
		vector<pair<PII, PII>> V;
		V.push_back(t[pos]);

		auto tmp = makeMove(pos, V);
		// zobacz czy jest sens robic kolejne ruchy
		if (tmp > best)
		{
			if (pos + 1 < n)
				dfs(pos + 1);
			else
				best = tmp;
		}
	}

	// 2 prostokaty poziome ]  [
	{
		vector<pair<PII, PII>> V;
		// lewy
		V.push_back(MP(MP(0, t[pos].first.second), MP(t[pos].first.first, t[pos].second.second)));
		// prawy
		V.push_back(MP(MP(t[pos].second.first, t[pos].first.second), MP(X, t[pos].second.second)));

		auto tmp = makeMove(pos, V);
		// zobacz czy jest sens robic kolejne ruchy
		if (tmp > best)
		{
			if (pos + 1 < n)
				dfs(pos + 1);
			else
				best = tmp;
		}
	}

	// 2 prostokaty pionowe H
	{
		vector<pair<PII, PII>> V;

		// dolny
		V.push_back(MP(MP(t[pos].first.first, 0), MP(t[pos].second.first, t[pos].first.second)));
		// gorny
		V.push_back(MP(MP(t[pos].first.first, t[pos].second.second), MP(t[pos].second.first, Y)));

		auto tmp = makeMove(pos, V);
		// zobacz czy jest sens robic kolejne ruchy
		if (tmp > best)
		{
			if (pos + 1 < n)
				dfs(pos + 1);
			else
				best = tmp;
		}
	}

	// 4 prostokaty w rogach
	{
		vector<pair<PII, PII>> V;
		// lewy dolny
		V.push_back(MP(MP(0, 0), MP(t[pos].first.first, t[pos].first.second)));
		// prawy dolny
		V.push_back(MP(MP(t[pos].second.first, 0), MP(X, t[pos].first.second)));
		// lewy gorny
		V.push_back(MP(MP(0, t[pos].second.second), MP(t[pos].first.first, Y)));
		// prawy gorny
		V.push_back(MP(MP(t[pos].second.first, t[pos].second.second), MP(X, Y)));

		auto tmp = makeMove(pos, V);
		// zobacz czy jest sens robic kolejne ruchy
		if (tmp > best)
		{
			if (pos + 1 < n)
				dfs(pos + 1);
			else
				best = tmp;
		}
	}
}

int main()
{
	scanf("%d%d%d", &n, &X, &Y);
	REP(i, n)
	{
		int x1, y1, x2, y2;
		scanf("%d%d%d%d", &x1, &y1, &x2, &y2);
		t[i] = MP(MP(min(x1, x2), min(y1, y2)), MP(max(x1, x2), max(y1, y2)));
	}

	states[0].push_back(MP(MP(0, 0), MP(X, Y)));
	dfs(0);

	printf("%lld\n", best);

	return 0;
}

// FOR GNU C++ use the following pattern:
// Uncomment the code below and change your main into main2
// It does not build in MS C++
// But it does increase the stack size from 256 MB on CF and uses GNU C++

//#include <Processthreadsapi.h>
//#include <iostream>
//#include <Synchapi.h>
//#include <windows.h>
//#include <process.h>
//
//DWORD WINAPI MyThreadFunction(LPVOID lpParam) {
//    main2(nullptr);
//    return 0;
//}
//int main() {
//    auto h = CreateThread(nullptr, 1024 << 20, MyThreadFunction, nullptr, STACK_SIZE_PARAM_IS_A_RESERVATION, nullptr);
//    WaitForSingleObject(h, INFINITE);
//}