#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const long long INF = (long long)1000000007 * 1000000007;
const long double eps = 1e-8;
const long double pi = acos(-1.0);
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  pair<int, int> a[3];
  for (int i = 0; i < 3; i++) {
    int x, y;
    cin >> x >> y;
    a[i] = {x, y};
  }
  sort(a, a + 3);
  vector<pair<int, int> > ans;
  for (int i = a[0].first; i < a[1].first; i++) {
    ans.push_back({i, a[0].second});
  }
  int le = min(a[0].second, a[1].second);
  int ri = max(a[0].second, a[1].second);
  for (int i = le; i <= ri; i++) {
    ans.push_back({a[1].first, i});
  }
  int c = a[2].second;
  for (int i = a[1].first + 1; i <= a[2].first; i++) {
    ans.push_back({i, c});
  }
  if (c > ri) {
    for (int i = ri + 1; i <= c; i++) {
      ans.push_back({a[1].first, i});
    }
  } else if (c < le) {
    for (int i = c; i <= le - 1; i++) {
      ans.push_back({a[1].first, i});
    }
  }
  cout << ans.size() << endl;
  for (int i = 0; i < ans.size(); i++) {
    cout << ans[i].first << " " << ans[i].second << endl;
  }
  return 0;
}
