#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie();
  int test = 1;
  while (test--) {
    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());
    vector<pair<int, int> > ans;
    for (int i = v[0].first; i < v[1].first; i++)
      ans.push_back({i, v[0].second});
    for (int i = v[1].first + 1; i <= v[2].first; i++)
      ans.push_back({i, v[2].second});
    pair<int, int> x;
    x.first = max(v[2].second, max(v[1].second, v[0].second));
    x.second = min(v[2].second, min(v[1].second, v[0].second));
    for (int i = x.second; i <= x.first; i++) ans.push_back({v[1].first, i});
    cout << ans.size() << endl;
    for (int i = 0; i < ans.size(); i++)
      cout << ans[i].first << " " << ans[i].second << endl;
  }
}
