#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9 + 10;
const int N = 3;
pair<int, int> p[4];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  for (int i = 0; i < N; i++) {
    cin >> p[i].first >> p[i].second;
  }
  set<pair<int, int>> res;
  int cur_size = inf;
  for (int dir = 0; dir < 2; dir++) {
    for (int i = 0; i < N; i++) {
      int x = p[i].first;
      int y = p[i].second;
      set<pair<int, int>> cur;
      for (int j = 0; j < N; j++) {
        if (i == j) continue;
        int xx = p[j].first;
        int yy = p[j].second;
        if (dir == 0) {
          while (xx < x) {
            cur.insert({xx, yy});
            xx++;
          }
          while (xx > x) {
            cur.insert({xx, yy});
            xx--;
          }
          cur.insert({xx, yy});
          while (yy < y) {
            cur.insert({xx, yy});
            yy++;
          }
          while (yy > y) {
            cur.insert({xx, yy});
            yy--;
          }
          cur.insert({xx, yy});
        } else {
          while (yy < y) {
            cur.insert({xx, yy});
            yy++;
          }
          while (yy > y) {
            cur.insert({xx, yy});
            yy--;
          }
          cur.insert({xx, yy});
          while (xx < x) {
            cur.insert({xx, yy});
            xx++;
          }
          while (xx > x) {
            cur.insert({xx, yy});
            xx--;
          }
          cur.insert({xx, yy});
        }
      }
      if (cur.size() < cur_size) {
        cur_size = cur.size();
        res = cur;
      }
    }
  }
  cout << res.size() << "\n";
  for (auto x : res) {
    cout << x.first << " " << x.second << "\n";
  }
  return 0;
}
