#include <bits/stdc++.h>
using namespace std;
int x[5], y[5], ans, i;
map<int, int> mp;
int main() {
  for (i = 1; i <= 3; i++) {
    cin >> x[i] >> y[i];
    mp[x[i]] = y[i];
  }
  sort(x + 1, x + 4);
  sort(y + 1, y + 4);
  ans = x[3] - x[1] + y[3] - y[1] + 1;
  cout << ans << endl;
  for (i = x[1]; i < x[2]; i++) {
    cout << i << " " << mp[x[1]] << endl;
  }
  for (i = x[3]; i > x[2]; i--) {
    cout << i << " " << mp[x[3]] << endl;
  }
  for (i = y[1]; i <= y[3]; i++) {
    cout << x[2] << " " << i << endl;
  }
  return 0;
}
