#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long t, n, m, k, i, x, y, g, f, sum, z, j, x1, x2, y1, y2, p, v, h, q;
  vector<pair<long long, long long> > a(3);
  cin >> a[0].first;
  cin >> a[0].second;
  cin >> a[2].first;
  cin >> a[2].second;
  cin >> a[1].first;
  cin >> a[1].second;
  sort(a.begin(), a.end());
  k = a[2].first - a[0].first;
  k = k + max(max(a[0].second, a[1].second), a[2].second) -
      min(min(a[0].second, a[1].second), a[2].second);
  cout << k + 1 << endl;
  for (i = a[0].first; i <= a[1].first; i++) {
    cout << i << " " << a[0].second << endl;
  }
  if (a[0].second > a[1].second) {
    for (i = a[0].second - 1; i >= a[1].second; i--) {
      cout << a[1].first << " " << i << endl;
    }
  } else {
    for (i = a[1].second; i >= a[0].second + 1; i--) {
      cout << a[1].first << " " << i << endl;
    }
  }
  if (a[2].second >= a[1].second and a[2].second >= a[0].second) {
    y = max(a[0].second, a[1].second);
    for (i = a[1].first + 1; i <= a[2].first; i++) {
      cout << i << " " << y << endl;
    }
    for (i = y + 1; i <= a[2].second; i++) {
      cout << a[2].first << " " << i << endl;
    }
  } else {
    if (a[2].second <= a[1].second and a[2].second <= a[0].second) {
      y = min(a[0].second, a[1].second);
      for (i = a[1].first + 1; i <= a[2].first; i++) {
        cout << i << " " << y << endl;
      }
      for (i = y - 1; i >= a[2].second; i--) {
        cout << a[2].first << " " << i << endl;
      }
    } else {
      for (i = a[1].first + 1; i <= a[2].first; i++) {
        cout << i << " " << a[2].second << endl;
      }
    }
  }
  return 0;
}
