#include <bits/stdc++.h>
using namespace std;
int x[11], y[11], cnt, used[1111][1111];
pair<int, pair<int, int> > a[11111];
pair<int, int> p[111];
int main() {
  cin >> x[1] >> y[1];
  cin >> x[2] >> y[2];
  cin >> x[3] >> y[3];
  p[1] = {x[1], y[1]};
  p[2] = {x[2], y[2]};
  p[3] = {x[3], y[3]};
  sort(p + 1, p + 3 + 1);
  cout << max({x[1], x[2], x[3]}) - min({x[1], x[2], x[3]}) +
              (max({y[1], y[2], y[3]}) - min({y[1], y[2], y[3]})) + 1
       << endl;
  for (int i = p[1].first; i <= p[2].first; i++) {
    cout << i << ' ' << p[1].second << endl;
    used[i][p[1].second] = 1;
  }
  for (int i = min(p[1].second, p[2].second);
       i <= max(p[1].second, p[2].second); i++) {
    if (!used[p[2].first][i]) cout << p[2].first << ' ' << i << endl;
    used[p[2].first][i] = 1;
  }
  for (int i = min(p[3].second, p[2].second);
       i <= max(p[3].second, p[2].second); i++) {
    if (!used[p[2].first][i]) cout << p[2].first << ' ' << i << endl;
    used[p[2].first][i] = 1;
  }
  for (int i = min(p[2].first, p[3].first); i <= max(p[2].first, p[3].first);
       i++) {
    if (!used[i][p[3].second]) cout << i << ' ' << p[3].second << endl;
    used[i][p[3].second] = 1;
  }
}
