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#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;
using LL = long long;
using PII = pair<int, int>;

struct Plot 
{
	PII left_corner;
	PII right_corner;
};

vector<vector<Plot>> make_next_territory(int x1, int y1, int x2, int y2, int X, int Y)
{
	int minX = min(x1, x2);
	int maxX = max(x1, x2);
	int minY = min(y1, y2);
	int maxY = max(y1, y2);

	vector<Plot> plots1;
	vector<Plot> plots2;
	vector<Plot> plots3;
	vector<Plot> plots4;

	Plot plot = { make_pair(minX, minY), make_pair(maxX, maxY) };
	plots1.push_back(plot);	

	if (minX > 0)
	{
		plot = { make_pair(0, minY), make_pair(minX, maxY) };
		plots2.push_back(plot);
	}

	plot = { make_pair(maxX, minY), make_pair(X, maxY) };
	plots2.push_back(plot);

	if (minY > 0)
	{
		plot = { make_pair(minX, 0), make_pair(maxX, minY) };
		plots3.push_back(plot);
	}

	plot = { make_pair(minX, maxY), make_pair(maxX, Y) };
	plots3.push_back(plot);

	if (minX > 0)
	{
		plot = { make_pair(0, maxY), make_pair(minX, Y) };
		plots4.push_back(plot);
	}

	if (minY > 0)
	{
		plot = { make_pair(maxX, 0), make_pair(X, minY) };
		plots4.push_back(plot);
	}

	if (minX > 0 && minY > 0)
	{
		plot = { make_pair(0, 0), make_pair(minX, minY) };
		plots4.push_back(plot);
	}

	plot = { make_pair(maxX, maxY), make_pair(X, Y) };
	plots4.push_back(plot);

	vector<vector<Plot>> next_territory{ plots1, plots2, plots3, plots4 };
	return next_territory;
}

vector<vector<Plot>> make_new_territories(vector<vector<Plot>> territories, vector<vector<Plot>> next_territory)
{
	vector<vector<Plot>> new_territories;

	for (int t1 = 0; t1 < territories.size(); ++t1)
	{
		for (int t2 = 0; t2 < next_territory.size(); ++t2)
		{
			vector<Plot> new_plots;

			for (int p1 = 0; p1 < territories[t1].size(); ++p1)
			{
				for (int p2 = 0; p2 < next_territory[t2].size(); ++p2)
				{
					int x1 = max(territories[t1][p1].left_corner.first, next_territory[t2][p2].left_corner.first);
					int y1 = max(territories[t1][p1].left_corner.second, next_territory[t2][p2].left_corner.second);
					int x2 = min(territories[t1][p1].right_corner.first, next_territory[t2][p2].right_corner.first);
					int y2 = min(territories[t1][p1].right_corner.second, next_territory[t2][p2].right_corner.second);

					if (x1 < x2 && y1 < y2)
					{
						Plot plot = { make_pair(x1, y1), make_pair(x2, y2) };
						new_plots.push_back(plot);
					}
				}
			}

			if (new_plots.size() > 0)
				new_territories.push_back(new_plots);
		}
	}

	return new_territories;
}

int main()
{
	int n, X, Y, x1, y1, x2, y2;

	cin >> n >> X >> Y;

	vector<vector<Plot>> territories(1, vector<Plot>(1));
	territories[0][0].left_corner = make_pair(0, 0);
	territories[0][0].right_corner = make_pair(X, Y);

	for (int i = 0; i < n; ++i)
	{
		cin >> x1 >> y1 >> x2 >> y2;

		vector<vector<Plot>> next_territory = make_next_territory(x1, y1, x2, y2, X, Y);

		territories = make_new_territories(territories, next_territory);
	}

	LL res = 0;

	for (int t = 0; t < territories.size(); ++t)
	{
		LL tmp = 0;

		for (int p = 0; p < territories[t].size(); ++p)
		{
			tmp += 1LL * (territories[t][p].right_corner.first - territories[t][p].left_corner.first)* (territories[t][p].right_corner.second - territories[t][p].left_corner.second);
		}

		res = max(res, tmp);
	}

	cout << res;

	return 0;
}