#include <bits/stdc++.h>
using namespace std;
pair<int, int> a[3];
int main() {
  for (int i = 0; i < 3; i++) scanf("%d%d", &a[i].first, &a[i].second);
  sort(a, a + 3);
  int mid = a[1].first;
  int mx = max({a[0].second, a[1].second, a[2].second});
  int mn = min({a[0].second, a[1].second, a[2].second});
  vector<pair<int, int> > pt;
  for (int i = mn; i <= mx; i++) pt.push_back({mid, i});
  for (int i = a[0].first; i <= mid; i++) pt.push_back({i, a[0].second});
  for (int i = a[2].first; i >= mid; i--) pt.push_back({i, a[2].second});
  sort(pt.begin(), pt.end());
  pt.resize(unique(pt.begin(), pt.end()) - pt.begin());
  printf("%d\n", (int)pt.size());
  for (int i = 0; i < pt.size(); i++)
    printf("%d %d\n", pt[i].first, pt[i].second);
}
