#include <bits/stdc++.h>
using namespace std;
using cd = complex<double>;
mt19937 rnd(chrono::system_clock::now().time_since_epoch().count());
pair<long long, long long> a[5];
int main() {
  for (long long i = 1; i <= 3; i++) {
    cin >> a[i].first >> a[i].second;
  }
  sort(a + 1, a + 1 + 3);
  set<pair<long long, long long> > c;
  long long x = a[1].first, y = a[1].second;
  c.insert({x, y});
  while (x != a[2].first) {
    x++;
    c.insert({x, y});
  }
  while (y != a[2].second) {
    if (y < a[2].second)
      y++;
    else
      y--;
    c.insert({x, y});
  }
  x = a[2].first, y = a[2].second;
  while (y != a[3].second) {
    if (y < a[3].second)
      y++;
    else
      y--;
    c.insert({x, y});
  }
  while (x != a[3].first) {
    x++;
    c.insert({x, y});
  }
  cout << c.size() << endl;
  for (auto i : c) {
    cout << i.first << " " << i.second << endl;
  }
}
