#include <bits/stdc++.h>
using namespace std;
const int N = 1000005;
void solve() {
  pair<long long int, long long int> p[3];
  for (long long int i = 0; i < 3; i++) cin >> p[i].first >> p[i].second;
  sort(p, p + 3);
  set<pair<long long int, long long int>> ans;
  ans.insert(make_pair(p[0].first, p[0].second));
  long long int crt_x = p[0].first, crt_y = p[0].second;
  while (crt_x != p[1].first) {
    crt_x++;
    ans.insert({crt_x, crt_y});
  }
  while (crt_y < p[1].second) {
    crt_y++;
    ans.insert({crt_x, crt_y});
  }
  while (crt_y > p[1].second) {
    crt_y--;
    ans.insert({crt_x, crt_y});
  }
  while (crt_y < p[2].second) {
    crt_y++;
    ans.insert({crt_x, crt_y});
  }
  while (crt_y > p[2].second) {
    crt_y--;
    ans.insert({crt_x, crt_y});
  }
  while (crt_x < p[2].first) {
    crt_x++;
    ans.insert({crt_x, crt_y});
  }
  cout << ans.size() << "\n";
  for (auto X : ans) cout << X.first << " " << X.second << "\n";
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  srand(time(NULL));
  ;
  long long int t = 1;
  while (t--) {
    solve();
  }
}
