#include <bits/stdc++.h>
using namespace std;
const long long INF = 2000000000LL;
const long double EPS = 1e-9;
vector<pair<int, int> > clear(vector<pair<int, int> > v) {
  vector<pair<int, int> > ret;
  int tox = v[1].first;
  int x = v[0].first, y = v[0].second;
  while (x <= tox) {
    ret.push_back({x, y});
    ++x;
  }
  int tx = v[1].first, ty = v[1].second;
  while (ty != y) {
    ret.push_back({tx, ty});
    (ty > y) ? --ty : ++ty;
  }
  tox = v[2].first;
  int toy = v[2].second;
  int p = v[0].second, q = v[1].second;
  if (p > q) swap(p, q);
  if (v[2].second >= p and v[2].second <= q) {
    while (x <= tox) {
      ret.push_back({x, toy});
      ++x;
    }
  } else if (v[2].second < p) {
    while (x <= tox) {
      ret.push_back({x, p});
      ++x;
    }
    while (toy != p) {
      ret.push_back({tox, toy});
      (toy > p) ? --toy : ++toy;
    }
  } else {
    while (x <= tox) {
      ret.push_back({x, q});
      ++x;
    }
    while (toy != q) {
      ret.push_back({tox, toy});
      (toy > q) ? --toy : ++toy;
    }
  }
  return ret;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  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());
  auto res = clear(v);
  sort((res).begin(), (res).end());
  res.erase(unique((res).begin(), (res).end()), res.end());
  cout << res.size() << "\n";
  for (auto x : res) cout << x.first << " " << x.second << "\n";
  return 0;
}
