#include <bits/stdc++.h>
using namespace std;
int main() {
  pair<int, int> t[3];
  int x[3], y[3];
  for (int i = 0; i < 3; ++i)
    cin >> t[i].first >> t[i].second, x[i] = t[i].first, y[i] = t[i].second;
  sort(x, x + 3);
  sort(y, y + 3);
  cout << y[2] - y[0] + x[2] - x[0] + 1 << "\n";
  for (int i = y[0]; i <= y[2]; ++i) cout << x[1] << " " << i << "\n";
  for (int i = 0; i < 3; ++i) {
    if (t[i].first < x[1]) {
      for (int j = t[i].first; j < x[1]; ++j)
        cout << j << " " << t[i].second << "\n";
    } else {
      for (int j = t[i].first; j > x[1]; --j)
        cout << j << " " << t[i].second << "\n";
    }
  }
}
