#include <bits/stdc++.h>
using namespace std;
const long long int p = 1e9 + 7;
int main() {
  int x, y, sum = 1;
  vector<pair<int, int> > vv;
  cin >> x >> y;
  vv.push_back(make_pair(x, y));
  cin >> x >> y;
  vv.push_back(make_pair(x, y));
  cin >> x >> y;
  vv.push_back(make_pair(x, y));
  sort(vv.begin(), vv.end());
  int x1 = vv[0].first;
  int y1 = vv[0].second;
  int x2 = vv[1].first;
  int y2 = vv[1].second;
  int x3 = vv[2].first;
  int y3 = vv[2].second;
  sum += x2 - x1 + abs(y2 - y1);
  if ((y3 >= y1 && y3 <= y2) || (y3 >= y2 && y3 <= y1))
    sum += x3 - x2;
  else {
    if (y3 > max(y2, y1))
      sum += x3 - x2 + y3 - max(y2, y1);
    else
      sum += x3 - x2 + min(y2, y1) - y3;
  }
  cout << sum << '\n';
  for (int i = 0; i <= x2 - x1; i++) cout << x1 + i << ' ' << y1 << '\n';
  if (y2 > y1) {
    for (int i = 1; i <= y2 - y1; i++) cout << x2 << ' ' << y1 + i << '\n';
  } else {
    for (int i = 1; i <= y1 - y2; i++) cout << x2 << ' ' << y1 - i << '\n';
  }
  if ((y3 >= y1 && y3 <= y2) || (y3 >= y2 && y3 <= y1)) {
    for (int i = 1; i <= x3 - x2; i++) cout << x2 + i << ' ' << y3 << '\n';
  } else {
    for (int i = 1; i <= x3 - x2; i++) cout << x2 + i << ' ' << y3 << '\n';
    if (y3 > max(y2, y1)) {
      for (int i = 1; i <= y3 - max(y2, y1); i++)
        cout << x2 << ' ' << max(y2, y1) + i << '\n';
    } else {
      for (int i = 1; i <= min(y2, y1) - y3; i++)
        cout << x2 << ' ' << min(y2, y1) - i << '\n';
    }
  }
  return 0;
}
