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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;

public class ple {

	public static class Area implements Comparable<Area> {
		int x1, x2, y1, y2;

		public Area(int x1, int x2, int y1, int y2) {
			super();
			this.x1 = x1;
			this.x2 = x2;
			this.y1 = y1;
			this.y2 = y2;
		}

		public String toStringDebug() {
			return "(" + x1 + "," + x2 + ";" + y1 + "," + y2 + ")";
		}

		public String toString() {
			return x1 + " " + x2 + " " + y1 + " " + y2;
		}

		public boolean isInside(int x, int y) {
			return x1 < x && x < x2 && y1 < y && y < y2;
		}

		public boolean isOverlaping(Area o) {
			// return (isInside(o.x1,o.y1) || isInside(o.x1,o.y2) ||
			// isInside(o.x2,o.y1) || isInside(o.x2,o.y2));
			return (x1 < o.x2 && x2 > o.x1 && y1 < o.y2 && y2 > o.y1);
			// return true;
		}

		public static Area minContainingArea(Area a, Area b) {
			return new Area(Math.min(a.x1, b.x1), Math.max(a.x2, b.x2), Math
					.min(a.y1, b.y1), Math.max(a.y2, b.y2));
		}

		@Override
		public int compareTo(Area o) {
			int res = 0;
			res = (res == 0 ? x1 - o.x1 : res);
			res = (res == 0 ? x2 - o.x2 : res);
			res = (res == 0 ? y1 - o.y1 : res);
			res = (res == 0 ? y2 - o.y2 : res);
			return res;
		}
	}

	public static class AreaSet {
		Set<Area> areas = new HashSet<Area>();

		public int size() {
			return areas.size();
		}

		public void add(Area area) {
			Area adding = area;
			while(adding != null) {
				Area overlaping = null;
				for (Area a : areas) {
					if (adding.isOverlaping(a)) {
						overlaping = a;
						break;
					}
				}
				if (overlaping == null) {
					areas.add(adding);
					adding = null;
				} else {
					areas.remove(overlaping);
					adding = Area.minContainingArea(overlaping, adding);
				}
			}
		}

		public void fill(Area[] states) {
			int num = 0;
			for (Area a : areas) {
				states[num++] = a;
			}
		}
	}

	public static void main(String[] args) throws IOException {
		BufferedReader reader = new BufferedReader(new InputStreamReader(
				System.in));
		StringTokenizer tokenizer;

		tokenizer = new StringTokenizer(reader.readLine());
		int n = Integer.parseInt(tokenizer.nextToken());

		// Area[] tribes = new Area[n];
		AreaSet areaSet = new AreaSet();

		for (int i = 0; i < n; i++) {
			tokenizer = new StringTokenizer(reader.readLine());
			int x1 = Integer.parseInt(tokenizer.nextToken());
			int x2 = Integer.parseInt(tokenizer.nextToken());
			int y1 = Integer.parseInt(tokenizer.nextToken());
			int y2 = Integer.parseInt(tokenizer.nextToken());
			// tribes[i] = new Area(x1, y1, x2, y2);
			areaSet.add(new Area(x1, x2, y1, y2));
			//if(i % 1000 == 0) {
			//	System.err.println(i / 1000);
			//}
		}

		Area[] states = new Area[areaSet.size()];
		areaSet.fill(states);
		Arrays.sort(states);
		System.out.println(states.length);
		for (int i = 0; i < states.length; i++) {
			System.out.println(states[i]);
		}

		/*
		 * Arrays.sort(tribes);
		 * 
		 * for(int i = 0; i < n; i++) { System.out.println(tribes[i]); }
		 */

		/*
		 * int minX = Integer.MAX_VALUE; int maxX = Integer.MIN_VALUE; Map<Integer,
		 * List<Integer>> begins = new HashMap<Integer, List<Integer>>(); Map<Integer,
		 * List<Integer>> ends = new HashMap<Integer, List<Integer>>();
		 * for(int i = 0; i < n; i++) { minX = Math.min(minX, tribes[i].x1);
		 * maxX = Math.max(maxX, tribes[i].x2);
		 * 
		 * if(begins.get(tribes[i].x1) == null) { begins.put(tribes[i].x1, new
		 * ArrayList<Integer>()); } begins.get(tribes[i].x1).add(i);
		 * 
		 * if(ends.get(tribes[i].x2) == null) { ends.put(tribes[i].x2, new
		 * ArrayList<Integer>()); } ends.get(tribes[i].x2).add(i); }
		 * 
		 * 
		 * IntervalTree<Integer> tree = new IntervalTree<Integer>(); for(int
		 * movingX = minX; movingX <= maxX; movingX++) { List<Integer> begin =
		 * begins.get(movingX); List<Integer> end = ends.get(movingX);
		 * 
		 * if(end != null) { for(Integer ) } }
		 */

		/*
		 * Interval over = new Interval<Integer>(5+0.001, 9-0.001);
		 * System.out.println(over); IntervalTree<Integer> tree = new
		 * IntervalTree<Integer>(); tree.insert(over); List res =
		 * tree.search(9.01, 15.99); System.out.println(res.size());
		 */
		// tree.
		// SegmentTree.DynamicSegmentTree<SegmentTree.Data.QuadrantData> tree =
		// new
		// SegmentTree.DynamicSegmentTree<SegmentTree.Data.QuadrantData>(null);//
		// = new DynamicSegmentTree
		// tree.
		// IntervalTree<Integer> tree = new IntervalTree<Integer>(null);
		// tree.
	}

}