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#include <cstdio>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <cmath>
using namespace std;

//int CALLS_GGETMAX=0, CALLS_SSETMAX=0;

struct Rect {
	int left, right, top, bottom; 
	bool operator == (const Rect& that) const
	{
		return left==that.left && right==that.right && top==that.top && bottom==that.bottom;
	}
	bool operator < (const Rect& that) const
	{
		if(left!=that.left) return left<that.left;
		if(right!=that.right) return right<that.right;
		if(bottom!=that.bottom) return bottom<that.bottom;
		return top<that.top;
	}
	Rect()
	{
		left=-1;
	}
	Rect(int l, int r, int b, int t) : left(l), right(r), top(t), bottom(b) {}
};
Rect maxRect(const Rect& r1, const Rect& r2)
{
	if(r1.left==-1) return r2;
	if(r2.left==-1) return r1;
	Rect sum;
	sum.left = min(r1.left, r2.left);
	sum.right = max(r1.right, r2.right);
	sum.bottom = min(r1.bottom, r2.bottom);
	sum.top = max(r1.top, r2.top);
	return sum;
}

struct HashRect
{
	size_t operator()(const Rect& r) const
	{
		return r.left * 4430159 ^ r.right*6271747 ^r.top*7187459 ^ r.bottom*1406707;
	}
};

struct QTree
{
	int size;
	unordered_map<Rect, Rect, HashRect> values;
	unordered_map<Rect, Rect, HashRect> maximums;
	QTree(int s) : size(s) {}
	
	void setMax(Rect r, Rect v)
	{
		ssetMax(Rect(0, size, 0, size), r, v);
	}
	void ssetMax(Rect at, Rect request, Rect value)
	{
		//CALLS_SSETMAX++;
		
		if(request.left<at.left) request.left = at.left;
		if(request.right>at.right) request.right = at.right;
		if(request.bottom<at.bottom) request.bottom = at.bottom;
		if(request.top>at.top) request.top = at.top;
		
		if(request.left<request.right && request.bottom<request.top){}else return;
				
		maximums[at] = maxRect(maximums[at], value);
		if(at==request)
		{
			values[at] = maxRect(values[at], value);
		}
		else
		{
			int midx = at.left + (at.right-at.left)/2;
			int midy = at.bottom + (at.top-at.bottom)/2;
			
			ssetMax(Rect(at.left, midx, at.bottom, midy), request, value);
			ssetMax(Rect(midx, at.right, at.bottom, midy), request, value);
			ssetMax(Rect(at.left, midx, midy, at.top), request, value);
			ssetMax(Rect(midx, at.right, midy, at.top), request, value);
		}
	}
	
	Rect getMax(Rect r, Rect biggerThan)
	{
		return ggetMax(Rect(0, size, 0, size), r, biggerThan);
	}
	Rect ggetMax(Rect at, Rect request, Rect biggerThan)
	{
		//CALLS_GGETMAX++;
		
		if(request.left<at.left) request.left = at.left;
		if(request.right>at.right) request.right = at.right;
		if(request.bottom<at.bottom) request.bottom = at.bottom;
		if(request.top>at.top) request.top = at.top;
		
		if(request.left<request.right && request.bottom<request.top){}else return Rect();
		
		if(!maximums.count(at)) return Rect();
		
		if(maxRect(maximums[at], biggerThan)==biggerThan) return Rect();
		
		if(at==request)
			return maximums[at];
		else if(values[at]==maximums[at])
			return maximums[at];
		else
		{
			int midx = at.left + (at.right-at.left)/2;
			int midy = at.bottom + (at.top-at.bottom)/2;
			
			Rect result = values[at];
			result = maxRect(result,
				ggetMax(Rect(at.left, midx, at.bottom, midy), request, 
					maxRect(result, biggerThan)
				)
			);
			result = maxRect(result,
				ggetMax(Rect(midx, at.right, at.bottom, midy), request, 
					maxRect(result, biggerThan)
				)
			);
			result = maxRect(result,
				ggetMax(Rect(at.left, midx, midy, at.top), request, 
					maxRect(result, biggerThan)
				)
			);
			result = maxRect(result,
				ggetMax(Rect(midx, at.right, midy, at.top), request, 
					maxRect(result, biggerThan)
				)
			);
			return result;
		}
	}
};

int main()
{
	int n;
	scanf("%d", &n);
	vector<Rect> tribes;	
	
	set<int> x, y;
	
	for(int i=0;i<n;i++)
	{
		Rect r;
		//printf("i=%d\n", i);
		scanf("%d%d%d%d", &r.left, &r.right, &r.bottom, &r.top);
		tribes.push_back(r);
		
		x.insert(r.left);
		x.insert(r.right);
		y.insert(r.bottom);
		y.insert(r.top);
	}
	
	map<int, int> map_x, map_y;
	vector<int> reverse_x{0}, reverse_y{0};
	for(int xv : x)
	{		
		map_x[xv] = reverse_x.size();
		reverse_x.push_back(xv);
	}
	for(int yv : y)
	{		
		map_y[yv] = reverse_y.size();
		reverse_y.push_back(yv);
	}
	int TREE_SIZE=8;
	while(TREE_SIZE<map_x.size() || TREE_SIZE<map_y.size())
		TREE_SIZE*=2;
	
	QTree t(TREE_SIZE);
	for(Rect& r : tribes)
	{
		Rect base = r;
		base.left = map_x[base.left];
		base.right = map_x[base.right];
		base.top = map_y[base.top];
		base.bottom = map_y[base.bottom];
		
		while(true)
		{
			Rect maks = maxRect(t.getMax(base, base), base);
			if(maks==base) break;
			base = maks;
		}
		t.setMax(base, base);
	}
	
	set<Rect> after;
	for(Rect& r : tribes)
	{
		Rect base = r;
		base.left = map_x[base.left];
		base.right = map_x[base.right];
		base.top = map_y[base.top];
		base.bottom = map_y[base.bottom];
		
		after.insert(
			t.getMax(base, Rect())
		);
	}
	
	printf("%ld\n", after.size());
	for(const Rect& r : after)
	{
		printf("%d %d %d %d\n",reverse_x[r.left], reverse_x[r.right], reverse_y[r.bottom], reverse_y[r.top]);
	}
	//fprintf(stderr, "n=%d: ss=%d, gg=%d | ss/(n*log^2(n))=%f, gg/n=%f\n", n, CALLS_SSETMAX, CALLS_GGETMAX,
	//	(double)CALLS_SSETMAX/n/(log(n)/log(2))/(log(n)/log(2)), (double)CALLS_GGETMAX/n);
}