#include <bits/stdc++.h>
using namespace std;
int main() {
  pair<int, int> a, b, c;
  cin >> a.first >> a.second;
  cin >> b.first >> b.second;
  cin >> c.first >> c.second;
  vector<pair<int, int> > v(3);
  v[0] = a;
  v[1] = b;
  v[2] = c;
  sort(v.begin(), v.end());
  a = v[0];
  b = v[1];
  c = v[2];
  if (a.second >= c.second) {
    if (b.second <= a.second && b.second >= c.second) {
      cout << a.second - c.second + c.first - a.first + 1 << "\n";
      int i;
      for (i = a.second; i >= b.second; i--) {
        cout << a.first << " " << i << "\n";
      }
      i++;
      int j;
      for (j = a.first + 1; j <= b.first; j++) {
        cout << j << " " << i << "\n";
      }
      j--;
      for (int k = b.second - 1; k >= c.second; k--) {
        cout << b.first << " " << k << "\n";
      }
      for (int v = b.first + 1; v <= c.first; v++) {
        cout << v << " " << c.second << "\n";
      }
    }
    if (b.second > a.second) {
      int j;
      cout << c.first - a.first + a.second - c.second + 1 + b.second - a.second
           << "\n";
      for (int j = a.first; j <= c.first; j++) {
        cout << j << " " << a.second << "\n";
      }
      for (int i = a.second - 1; i >= c.second; i--) {
        cout << c.first << " " << i << "\n";
      }
      for (int k = b.second; k > a.second; k--) {
        cout << b.first << " " << k << "\n";
      }
    }
    if (b.second < c.second) {
      int j;
      cout << c.first - a.first + a.second - c.second + 1 + c.second - b.second
           << "\n";
      for (int j = a.first; j <= c.first; j++) {
        cout << j << " " << c.second << "\n";
      }
      for (int i = a.second; i >= c.second + 1; i--) {
        cout << a.first << " " << i << "\n";
      }
      for (int k = b.second; k < c.second; k++) {
        cout << b.first << " " << k << "\n";
      }
    }
  }
  if (c.second > a.second) {
    if (b.second <= c.second && b.second >= a.second) {
      cout << c.second - a.second + c.first - a.first + 1 << "\n";
      int i;
      for (i = c.second; i >= b.second; i--) {
        cout << c.first << " " << i << "\n";
      }
      i++;
      int j;
      for (j = c.first - 1; j >= b.first; j--) {
        cout << j << " " << i << "\n";
      }
      j++;
      int k;
      for (k = i - 1; k >= a.second; k--) {
        cout << j << " " << k << "\n";
      }
      for (int v = b.first - 1; v >= a.first; v--) {
        cout << v << " " << a.second << "\n";
      }
    }
    if (b.second > c.second) {
      int j;
      cout << c.first - a.first + c.second - a.second + 1 + b.second - c.second
           << "\n";
      for (int j = a.first; j <= c.first; j++) {
        cout << j << " " << c.second << "\n";
      }
      for (int i = c.second - 1; i >= a.second; i--) {
        cout << a.first << " " << i << "\n";
      }
      for (int k = b.second; k > c.second; k--) {
        cout << b.first << " " << k << "\n";
      }
    }
    if (b.second < a.second) {
      int j;
      cout << c.first - a.first + c.second - a.second + 1 + a.second - b.second
           << "\n";
      for (int j = a.first; j <= c.first; j++) {
        cout << j << " " << a.second << "\n";
      }
      for (int i = c.second; i >= a.second + 1; i--) {
        cout << c.first << " " << i << "\n";
      }
      for (int k = b.second; k < a.second; k++) {
        cout << b.first << " " << k << "\n";
      }
    }
  }
  return 0;
}
