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#include <cstdio>
#include <list>
#include <algorithm>
using namespace std;

int n;
struct Rect { int x1,x2,y1,y2; };
list<Rect> s;

inline bool operator< (const Rect& lhs, const Rect& rhs) {
	if (lhs.x1 != rhs.x1)
		return lhs.x1 < rhs.x1;
	if (lhs.x2 != rhs.x2)
		return lhs.x2 < rhs.x2;
	if (lhs.y1 != rhs.y1)
		return lhs.y1 < rhs.y1;
	return lhs.y2 < rhs.y2;
}

bool intersect(const Rect& r1, const Rect& r2)
{
	return r1.x2 > r2.x1 && r1.x1 < r2.x2 &&
		r1.y2 > r2.y1 && r1.y1 < r2.y2; 
}

void insert(Rect& r)
{
	bool changed = true;
	while (changed) {
		changed = false;
		for (auto it = s.begin(); it != s.end(); it++) {
			if (intersect(r, *it)) {
				r.x1 = min(r.x1, it->x1);
				r.x2 = max(r.x2, it->x2);
				r.y1 = min(r.y1, it->y1);
				r.y2 = max(r.y2, it->y2);
				changed = true;
				s.erase(it);
				break;
			}
		}
		if (!changed)
			s.push_front(r);
	}
}

int main()
{
	Rect r;
	scanf("%d", &n);
	for (int i = 0; i < n; i++) {
		scanf("%d%d%d%d", &r.x1, &r.x2, &r.y1, &r.y2);
		insert(r);
	}
	s.sort();
	printf("%d\n", s.size());
	for (auto it = s.begin(); it != s.end(); it++)
		printf("%d %d %d %d\n", it->x1, it->x2, it->y1, it->y2);
	
	return 0;
}