1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
#include <cstdio>
#include <vector>
#include <algorithm>
#include <stack>
using namespace std;


bool broken_v[500001];
bool broken_h[500001];

struct line{
	int id;     // rect id
	int c;      // distance from edge
	bool start; // is it closer or further from the edge

	bool operator<(line& otherLine){
		return c < otherLine.c;
	}
};

vector<line> hlines;
vector<line> vlines;

struct layer{
	int id; // element on the top
	int val;  // aggregate size
	int b;  // brokens when last aggregated
};

stack<layer> layers;

int n;
int xa, ya, xb, yb, tx, ty;

int hmax, vmax;

int main(){
	scanf("%d %d %d", &n, &tx, &ty);
	for (int i = 0; i < n; ++i) {
		line h_s, h_e, v_s, v_e;
		scanf("%d %d %d %d", &xa, &ya, &xb, &yb);
		h_s.id = h_e.id = v_s.id = v_e.id = i+1;
		h_s.start = v_s.start = true;
		h_e.start = v_e.start = false;
		
		if (xa < xb) {
			h_s.c = xa;
			h_e.c = xb;
		} else {
			h_s.c = xb;
			h_e.c = xa;
		}
		
		if (ya < yb) {
			v_s.c = ya;
			v_e.c = yb;
		} else {
			v_s.c = yb;
			v_e.c = ya;
		}
		
		hlines.push_back(h_s);
		hlines.push_back(h_e);
		vlines.push_back(v_s);
		vlines.push_back(v_e);
	}
	
	line hstart, hend, vstart, vend;
	hstart.id = hend.id = vstart.id = vend.id = 0;
	hstart.c = vstart.c = 0;
	hend.c = tx;
	vend.c = ty;
	hstart.start = vstart.start = true;
	hend.start = vend.start = false;
	
	hlines.push_back(hstart);
	hlines.push_back(hend);
	vlines.push_back(vstart);
	vlines.push_back(vend);
	
	sort(hlines.begin(), hlines.end());
	sort(vlines.begin(), vlines.end());
	
	/*
	printf("HORIZONTALS:\n");
	for(int j = 0; j < 2*(n+1); ++j){
		line l = hlines[j];
		char c;
		if(l.start){
			c = 's';
		} else {
			c = 'e';
		}
		
		printf("%d %d %c\n", l.id, l.c, c);
	}
	
	printf("\nVERTICALS:\n");
	for(int j = 0; j < 2*(n+1); ++j){
		line l = vlines[j];
		char c;
		if(l.start){
			c = 's';
		} else {
			c = 'e';
		}
		
		printf("%d %d %c\n", l.id, l.c, c);
	}
	* */
	
	int totalLines = 2*(n+1);
	
	stack<layer> hlayers;
	int brokens = 0;

	for (int i = 0; i < totalLines - 1; ++i){
		line l = hlines[i];
		int cur_size = hlines[i+1].c - l.c;
		
		if(l.start){
			layer r;
			r.id = l.id;
			r.val = cur_size;
			r.b = brokens;
			hlayers.push(r);
		} else {
			broken_h[l.id] = true;
			brokens++;
			while(broken_h[hlayers.top().id]){
					//layer m = hlayers.top();
					//printf("%d %d %d\n", m.id, m.val, m.b);
				if (hlayers.top().val > hmax) {
					hmax = hlayers.top().val;
				}
				hlayers.pop();
				brokens--;
			}
			
			if(hlayers.top().b == brokens){
				hlayers.top().val += cur_size;
			} else {
					//layer m = hlayers.top();
					//printf("%d %d %d\n", m.id, m.val, m.b);
				if (hlayers.top().val > hmax) {
					hmax = hlayers.top().val;
				}
				hlayers.top().val = cur_size;
				hlayers.top().b = brokens;
			}
		}
	}
					//layer m = hlayers.top();
					//printf("%d %d %d\n", m.id, m.val, m.b);
	if (hlayers.top().val > hmax) {
		hmax = hlayers.top().val;
	}
	
	stack<layer> vlayers;
	brokens = 0;
	
	for (int i = 0; i < totalLines - 1; ++i){
		line l = vlines[i];
		int cur_size = vlines[i+1].c - l.c;
		
		if(l.start){
			layer r;
			r.id = l.id;
			r.val = cur_size;
			r.b = brokens;
			vlayers.push(r);
		} else {
			broken_v[l.id] = true;
			brokens++;
			while(broken_v[vlayers.top().id]){
					//m = vlayers.top();
					//printf("%d %d %d\n", m.id, m.val, m.b);
				if (vlayers.top().val > vmax) {
					vmax = vlayers.top().val;
				}
				vlayers.pop();
				brokens--;
			}
			
			if(vlayers.top().b == brokens){
				vlayers.top().val += cur_size;
			} else {
					//m = vlayers.top();
					//printf("%d %d %d\n", m.id, m.val, m.b);
				if (vlayers.top().val > vmax) {
					vmax = vlayers.top().val;
				}
				vlayers.top().val = cur_size;
				vlayers.top().b = brokens;
			}
		}
	}
					//m = vlayers.top();
					//printf("%d %d %d\n", m.id, m.val, m.b);
	if (vlayers.top().val > vmax) {
		vmax = vlayers.top().val;
	}
	
	long long int g = (long long int)hmax * (long long int)vmax;
	
	printf("%lld\n", g);	
	return 0;
}