#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  vector<pair<int, int> > pts(3, {0, 0});
  cin >> pts[0].first >> pts[0].second >> pts[1].first >> pts[1].second >>
      pts[2].first >> pts[2].second;
  sort(pts.begin(), pts.end());
  pair<int, int> act = pts[0];
  vector<pair<int, int> > ans = {act};
  while (act.first < pts[1].first) {
    act.first++;
    ans.push_back(act);
  }
  if (act.second < pts[1].second) {
    while (act.second < pts[1].second) {
      act.second++;
      ans.push_back(act);
    }
  }
  if (act.second > pts[1].second) {
    while (act.second > pts[1].second) {
      act.second--;
      ans.push_back(act);
    }
  }
  if (act.second <= pts[2].second) {
    act.second = min(pts[2].second, max(pts[0].second, pts[1].second));
    while (act.second < pts[2].second) {
      act.second++;
      ans.push_back(act);
    }
  } else {
    act.second = max(pts[2].second, min(pts[0].second, pts[1].second));
    while (act.second > pts[2].second) {
      act.second--;
      ans.push_back(act);
    }
  }
  while (act.first < pts[2].first) {
    act.first++;
    ans.push_back(act);
  }
  cout << ans.size() << "\n";
  for (auto aa : ans) cout << aa.first << " " << aa.second << "\n";
  return 0;
}
