#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  ;
  vector<pair<int, int> > a(3);
  int x[3], y[3];
  for (int i = 0; i < 3; i++) {
    cin >> a[i].first >> a[i].second;
    x[i] = a[i].first;
    y[i] = a[i].second;
  }
  sort(x, x + 3);
  sort(y, y + 3);
  cout << x[2] - x[0] + 1 + y[2] - y[0] << endl;
  for (int i = 0; i < 3; i++) {
    if (a[i].first < x[1]) {
      for (int j = a[i].first; j < x[1]; j++) {
        cout << j << " " << a[i].second << endl;
      }
    } else if (a[i].first > x[1]) {
      for (int j = a[i].first; j > x[1]; j--)
        cout << j << " " << a[i].second << endl;
    }
    if (a[i].second < y[1]) {
      for (int j = a[i].second; j < y[1]; j++) {
        cout << x[1] << " " << j << endl;
      }
    } else if (a[i].second > y[1]) {
      for (int j = a[i].second; j > y[1]; j--) cout << x[1] << " " << j << endl;
    }
  }
  cout << x[1] << " " << y[1] << endl;
  return 0;
}
