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#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <vector>

using namespace std;

struct prost {
	int x1, x2;
	int y1, y2;
};

bool cmp1(struct prost a, struct prost b) {
	if (a.x1 == b.x1 && a.x2 == b.x2 && a.y1 == b.y1) return a.y2 < b.y2;
	if (a.x1 == b.x1 && a.x2 == b.x2) return a.y1 < b.y1;
	if (a.x1 == b.x1) return a.x2 < b.x2;
	return a.x1 < b.x1;	
}

vector<prost> wynik;

bool czyPrzeciecie(struct prost& a, struct prost& b)
{
	if (b.x1 <= a.x1 && a.x1 < b.x2 && b.y1 < a.y2 && a.y2 <= b.y2) {
		return true;
	}
	if (b.x1 < a.x2 && a.x2 <= b.x2 && b.y1 <= a.y1 && a.y1 < b.y2) {
		return true;
	}
	if (a.x1 < b.x2 && b.x2 <= a.x2 && a.y1 < b.y2 && b.y2 <= a.y2) {
		return true;
	}
	if (a.x1 <= b.x1 && b.x1 < a.x2 && a.y1 <= b.y1 && b.y1 < a.y2) {
		return true;
	}
	if (b.x1 <= a.x1 && a.x1 < b.x2 && b.y1 <= a.y1 && a.y1 < b.y2) {
		return true;
	}
	if (a.x1 <= b.x1 && b.x1 < a.x2 && a.y1 < b.y2 && b.y2 <= a.y2) {
		return true;
	}
	if (a.x1 <= b.x1 && a.x2 >= b.x2 && b.y1 <= a.y1 && b.y2 >= a.y2) {
		return true;
	}
	if (b.x1 <= a.x1 && b.x2 >= a.x2 && a.y1 <= b.y1 && a.y2 >= b.y2) {
		return true;
	}
	if (a.x1 < b.x2 && b.x2 <= a.x2 && a.y1 < b.y2 && b.y2 <= a.y2) {
		return true;
	}
	if (a.x1 < b.x2 && b.x2 <= a.x2 && a.y1 <= b.y1 && b.y1 < a.y2) {
		return true;
	}
	return false;
}

void dodajDoWyniku(struct prost& a) {
	bool dodano = true;
	for (int i = 0; i < wynik.size() && dodano; i++) {
		if (czyPrzeciecie(wynik[i], a)) {
			struct prost nowy;
			nowy.x1 = min(a.x1, wynik[i].x1);
			nowy.x2 = max(a.x2, wynik[i].x2);
			nowy.y1 = min(a.y1, wynik[i].y1);
			nowy.y2 = max(a.y2, wynik[i].y2);
			wynik.erase(wynik.begin() + i);
			dodajDoWyniku(nowy);
			dodano = false;
		}
	}
	if (dodano) wynik.push_back(a);
}

int main() {
	int n;
	scanf("%d", &n);
	int x1, x2, y1, y2;
	for (int i = 0; i < n; i++) {
		scanf("%d%d%d%d", &x1, &x2, &y1, &y2);
		struct prost nowyProstokat;
		nowyProstokat.x1 = x1;
		nowyProstokat.x2 = x2;
		nowyProstokat.y1 = y1;
		nowyProstokat.y2 = y2;
		dodajDoWyniku(nowyProstokat);
	}
	sort(wynik.begin(), wynik.end(), cmp1);
	printf("%d\n", wynik.size());
	for (int i = 0; i < wynik.size(); i++) {
		printf("%d %d %d %d\n", wynik[i].x1, wynik[i].x2, wynik[i].y1, wynik[i].y2);
	}
	return 0;
}