source_code: import java.util.*;
  import java.io.*;
  
  public class Three{
      public static void main(String[] args) {
  	Scanner in = new Scanner (System.in);
  	PrintWriter out = new PrintWriter(System.out);
  
  	pair[] points = new pair [3];
  	for (int i = 0; i < 3; ++i) {
  	    int x = in.nextInt();
  	    int y = in.nextInt();
  	    points[i] = new pair (x, y);
  	}
  
  	Arrays.sort(points);
  
  	int MaxY = Math.max(Math.max(points[0].y, points[1].y), points[2].y);
  	int MinY = Math.min(Math.min(points[0].y, points[1].y), points[2].y);
  
  	out.println(MaxY - MinY + points[2].x - points[0].x + 1);
  	for (int i = MinY; i <= MaxY; ++i)
  	    out.println(points[1].x + " " + i);
  	for (int i = points[0].x; i < points[1].x; ++i)
  	    out.println(i + " " + points[0].y);
  	for (int i = points[1].x + 1; i <= points[2].x; ++i)
  	    out.println(i + " " + points[2].y);
  	
  	out.close();
      }
  
      public static class pair implements Comparable<pair> {
  	int x, y;
  	public pair (int x_, int y_) {
  	    x = x_; y = y_;
  	}
  
  	@Override
  	public int compareTo(pair o) {
  	    return x - o.x;
  	}
      }
  }
  