#include <bits/stdc++.h>
using namespace std;
int dis(pair<int, int>& a, pair<int, int>& b) {
  return abs(a.first - b.first) + abs(a.second - b.second);
}
int main() {
  vector<pair<int, int> > v(3);
  for (int i = 0; i < 3; i++) cin >> v[i].first >> v[i].second;
  sort(v.begin(), v.end());
  set<pair<int, int> > p;
  for (int i = v[0].first; i <= v[1].first; i++)
    p.insert(make_pair(i, v[0].second));
  for (int i = v[2].first; i >= v[1].first; i--)
    p.insert(make_pair(i, v[2].second));
  int minn = min(v[0].second, min(v[1].second, v[2].second));
  int maxn = max(v[0].second, max(v[1].second, v[2].second));
  for (int j = minn; j <= maxn; j++) p.insert(make_pair(v[1].first, j));
  cout << p.size() << endl;
  for (auto it : p) cout << it.first << " " << it.second << endl;
  return 0;
}
