#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
pair<long long, long long> po[3];
vector<pair<long long, long long> > ou;
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  for (long long i = 0; i < 3; i++) cin >> po[i].first >> po[i].second;
  sort(po, po + 3);
  for (long long i = 0; i < po[1].first - po[0].first; i++)
    ou.push_back({po[0].first + i, po[0].second});
  long long a = po[0].second, b = po[1].second, c = po[2].second;
  if (a > b) swap(a, b);
  for (long long i = a; i <= b; i++) ou.push_back({po[1].first, i});
  for (long long i = po[1].first + 1; i <= po[2].first; i++)
    ou.push_back({i, po[2].second});
  if (po[2].second > b) {
    for (long long i = b + 1; i <= po[2].second; i++)
      ou.push_back({po[1].first, i});
  } else if (po[2].second < a) {
    for (long long i = po[2].second; i < a; i++) ou.push_back({po[1].first, i});
  }
  cout << ((long long)ou.size()) << '\n';
  for (long long i = 0; i < ((long long)ou.size()); i++)
    cout << ou[i].first << " " << ou[i].second << '\n';
  return 0;
}
