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#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cmath>
#include <string>
#include <cstring>
using namespace std;

typedef long long int LL;
typedef long double LD;
typedef vector<int> VI;
typedef vector<LL> VLL;
typedef vector<LD> VLD;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef vector<PII> VPII;

const int INF = 1000000001;
const LD EPS = 10e-9;

#define FOR(x, b, e) for(int x = b; x <= (e); ++x)
#define FORD(x, b, e) for(int x = b; x >= (e); --x)
#define REP(x, n) for(int x = 0; x < (n); ++x)
#define VAR(v, n) __typeof(n) v = (n)
#define ALL(c) (c).begin(), (c).end()
#define SIZE(x) ((int)(x).size())
#define FORE(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)
#define MP make_pair
#define PB push_back
#define ST first
#define ND second
#define abs(a) ((a)<0 ? -(a) : (a))
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))

const int MAX_N = 100005;

struct rect
{
	int x1, x2, y1, y2;
	
	rect(int _x1 = 0, int _x2 = 0, int _y1 = 0, int _y2 = 0) : x1(_x1), x2(_x2), y1(_y1), y2(_y2) {	}
}res[MAX_N];

bool operator<(const rect &a, const rect &b)
{
	if(a.x1 == b.x1)
	{
		if(a.x2 == b.x2)
		{
			if(a.y1 == b.y1) return a.y2 < b.y2;
			return a.y1 < b.y1;
		}
		return a.x2 < b.x2;
	}
	return a.x1 < b.x1;
}

list<rect> ple;
int n, xx1, xx2, yy1, yy2, resN;

bool intersect(const rect &a, const rect &b)
{	
	if(a.x1 <= b.x1)
	{
		if(a.y1 <= b.y1)
		{
			return (b.x1 < a.x2 && b.y1 < a.y2);
		}
		return (b.x1 < a.x2 && a.y1 < b.y2); 
	}
	
	if(a.y1 <= b.y1)
	{
		return (a.x1 < b.x2 && b.y1 < a.y2);
	}
	return (a.x1 < b.x2 && a.y1 < b.y2); 
}

int main()
{
	scanf("%d", &n);
	REP(i, n)
	{
		scanf("%d %d %d %d", &xx1, &xx2, &yy1, &yy2);
		ple.push_back(rect(xx1, xx2, yy1, yy2));	
	}
	
	size_t lastSize = ple.size()+1;
	while(ple.size() < lastSize)
	{
		lastSize = ple.size();
		for(auto itF = ple.begin(); itF != ple.end(); ++itF)
		{
			bool bbreak = 0;
			for(auto itS = next(itF); itS != ple.end(); ++itS)
			{
				if(intersect(*itF, *itS))
				{
					bbreak = 1;
					rect coverRect(min(itF->x1, itS->x1), max(itF->x2, itS->x2), min(itF->y1, itS->y1), max(itF->y2, itS->y2));	
					ple.erase(itF);
					ple.erase(itS);
					ple.push_front(coverRect);	
					
					//cout << "sie przecielo" << endl;
					break;
				}		
			}
			
			if(bbreak)
			{
				break;
			}
		}
	}
	
	for(auto it = ple.cbegin(); it != ple.cend(); ++it)
	{
		res[resN++] = *it;
	}
	sort(res, res+resN);
	
	printf("%d\n", ple.size());
	REP(i, resN)
	{
		printf("%d %d %d %d\n", res[i].x1, res[i].x2, res[i].y1, res[i].y2);
	}
	//system("pause");
	return 0;
}