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// Krzysztof Piesiewicz
// Plemiona [B] PA 2014
#include <cstdio>
#include <algorithm>
#include <set>
using namespace std;

const int MAX_N = 100007, MAX_SIZE = 1 << 20, DB = 0;

class Rect {
public:
	int id, x[ 2 ], y[ 2 ];
	bool isCountry;
};

class Apex {
public:
	struct CmpY {
		inline bool operator() ( Rect *a, Rect *b ) {
			if( a->y[ 1 ] == b->y[ 1 ] )
				return a < b;
			return a->y[ 1 ] > b->y[ 1 ];
		}
	};
	
	int l, r;
	Apex *left, *right;
	set< Rect*, CmpY > s[ 2 ];
	
	Apex( int p, int k ) : l( p ), r( k ) {
		if( r - l >= 2 ) {
			left = new Apex( l, (l + r) / 2 );
			right = new Apex( (l + r) / 2, r );
		}
	}
};

struct CmpLex {
	int num[ 2 ][ 4 ];
	Rect *r[ 2 ];
	inline bool operator()( Rect *a, Rect *b ) {
		r[ 0 ] = a;
		r[ 1 ] = b;
		for( int i = 0; i < 2; i++ )
			for( int j = 0; j < 2; j++ ) {
				num[ i ][ j ] = r[ i ]->x[ j ];
				num[ i ][ 2 + j ] = r[ i ]->y[ j ];
			}
		for( int i = 0; i < 4; i++ )
			if( num[ 0 ][ i ] != num[ 1 ][ i ] )
				return num[ 0 ][ i ] < num[ 1 ][ i ];
		return true;
	}
} cmpLex;

inline bool operator<( Rect a, Rect b ) {
	return a.y[ 0 ] < b.y[ 0 ];
}

Rect* collis( Apex *t, Rect *r ) {
	Rect *res = NULL;
	if( !t->s[ 1 ].empty() && (*t->s[ 1 ].begin())->y[ 1 ] > r->y[ 0 ] )
		res = *t->s[ 1 ].begin();
	else {
		if( r->x[ 0 ] <= t->l  && r->x[ 1 ] >= t->r ) {
			if( !t->s[ 0 ].empty() && (*t->s[ 0 ].begin())->y[ 1 ] > r->y[ 0 ] )
				res = *t->s[ 0 ].begin();
		}
		else {
			if( t->left->r > r->x[ 0 ] ) res = collis( t->left, r );
			if( t->left->r < r->x[ 1 ] && res == NULL ) res = collis( t->right, r );
		}
	}
	return res;
}

void insert( Apex *t, Rect *r ) {
	if( DB ) printf( "id %d, %d-%d\n", r->id, t->l, t->r);
	if( r->x[ 0 ] <= t->l && r->x[ 1 ] >= t->r )
		t->s[ 1 ].insert( r );
	else
		t->s[ 0 ].insert( r );
	if( t->l < r->x[ 0 ] || t->r > r->x[ 1 ] ) {
		if( t->left->r > r->x[ 0 ] ) insert( t->left, r );
		if( t->left->r < r->x[ 1 ] ) insert( t->right, r );
	}
}

void erase( Apex *t, Rect *r ) {
	if( r->x[ 0 ] <= t->l && r->x[ 1 ] >= t->r )
		t->s[ 1 ].erase( r );
	else
		t->s[ 0 ].erase( r );
	if( t->l < r->x[ 0 ] || t->r > r->x[ 1 ] ) {
		if( t->left->r > r->x[ 0 ] ) erase( t->left, r );
		if( t->left->r < r->x[ 1 ] ) erase( t->right, r );
	}
}

void countCountries( Apex *t ) {
	for( int i = 0; i < 2; i++ )
		for( auto it = t->s[ i ].begin(); it != t->s[ i ].end(); it++ )
			(*it)->isCountry = true;
	if( t->l + 1 < t->r ) {
		countCountries( t->left );
		countCountries( t->right );
	}
}

void print( Apex *t, int lvl ) {
	for( int i = 0; i < lvl; i++ )
		printf( "  " );
	printf( "%d - %d\n", t->l, t->r );
	for( int i = 0; i < 2; i++ ) {
		for( int j = 0; j < lvl; j++ )
			printf( "  " );
		printf( "  %d : ", i );
		for( auto it = t->s[ i ].begin(); it != t->s[ i ].end(); it++ )
			printf( "(%d, %d-%d) ", (*it)->id, (*it)->y[ 0 ], (*it)->y[ 1 ] );
		printf( "\n" );
	}
	if( t->left != NULL )
		print( t->left, lvl + 1 );
	if( t->right != NULL )
		print( t->right, lvl + 1 );
}

int n, size = 1;
Apex *t;
Rect r[ MAX_N ], *rct;
vector< Rect* > res;

int main() {
	scanf( "%d", &n );
	for( int i = 0; i < n; i++ ) {
		for( int j = 0; j < 2; j++ )
			scanf( "%d", &r[ i ].x[ j ] );
		for( int j = 0; j < 2; j++ )
			scanf( "%d", &r[ i ].y[ j ] );
		r[ i ].id = i;
	}
	sort( r, r + n );
	t = new Apex( 0, MAX_SIZE );
	
	for( int i = 0; i < n; i++ ) {
		if( DB ) {
			printf( "i %d ->>\n", i );
			print( t, 0 );
			printf( "\n\n" );
		}
		rct = collis( t, &r[ i ] );
		if( rct != NULL ) {
			erase( t, rct );
			r[ i ].x[ 0 ] = min( r[ i ].x[ 0 ], rct->x[ 0 ] );
			r[ i ].y[ 0 ] = min( r[ i ].y[ 0 ], rct->y[ 0 ] );
			r[ i ].x[ 1 ] = max( r[ i ].x[ 1 ], rct->x[ 1 ] );
			r[ i ].y[ 1 ] = max( r[ i ].y[ 1 ], rct->y[ 1 ] );
			i--;
		}
		else
			insert( t, &r[ i ] );
	}
	countCountries( t );
	for( int i = 0; i < n; i++ )
		if( r[ i ].isCountry )
			res.push_back( &r[ i ] );
	
	sort( res.begin(), res.end(), cmpLex );
	printf( "%ld\n", res.size() );
	for( auto it = res.begin(); it != res.end(); it++ )
		printf( "%d %d %d %d\n", (*it)->x[ 0 ], (*it)->x[ 1 ], (*it)->y[ 0 ], (*it)->y[ 1 ] );
	return 0;
}