#include <bits/stdc++.h>
using namespace std;
void path(long long x, long long y, long long a, long long b, bool chk) {
  long long direction;
  long long ydirection;
  if (b >= y)
    ydirection = 1;
  else
    ydirection = 0;
  if (a >= x)
    direction = 1;
  else
    direction = 0;
  if (direction) {
    for (long long i = x; i < a + 1; i++) {
      if (chk && i == x) continue;
      cout << i << " " << y << "\n";
    }
    if (ydirection) {
      for (long long i = y + 1; i < b + 1; i++) {
        cout << a << " " << i << "\n";
      }
    } else {
      for (long long i = y - 1; i >= b; i--) {
        cout << a << " " << i << "\n";
      }
    }
  } else {
    for (long long i = x; i >= a; i--) {
      if (i == x && chk) continue;
      cout << i << " " << y << "\n";
    }
    if (ydirection) {
      for (long long i = y + 1; i < b + 1; i++) {
        cout << a << " " << i << "\n";
      }
    } else {
      for (long long i = y - 1; i >= b; i--) {
        cout << a << " " << i << "\n";
      }
    }
  }
}
bool middle(long long a, long long b, long long c, long long d, long long e,
            long long f) {
  if (c >= min(a, e) && c <= max(a, e) && d >= min(b, f) && d <= max(b, f))
    return true;
  else
    return false;
}
void solve() {
  vector<pair<long long, long long>> v(3);
  for (long long i = 0; i < 3; i++) {
    long long t, y;
    cin >> t >> y;
    v[i] = {t, y};
  }
  long long x1 = v[0].first, y1 = v[0].second, x2 = v[1].first,
            y2 = v[1].second, x3 = v[2].first, y3 = v[2].second;
  if (middle(x1, y1, x3, y3, x2, y2)) {
    cout << abs(v[1].second - v[0].second) + abs(v[1].first - v[0].first) + 1
         << "\n";
    path(x1, y1, x3, y3, 0);
    path(x3, y3, x2, y2, 1);
    return;
  }
  vector<pair<long long, long long>> chk;
  vector<pair<long long, long long>> dv(v.begin(), v.end() - 1);
  long long mini = min(v[1].first, v[0].first);
  long long maxi = max(v[1].first, v[0].first);
  while (mini != (maxi + 1)) {
    chk.push_back({mini, v[0].second});
    chk.push_back({mini, v[1].second});
    mini++;
  }
  mini = min(v[1].second, v[0].second);
  maxi = max(v[1].second, v[0].second);
  while (mini != (maxi + 1)) {
    chk.push_back({v[0].first, mini});
    chk.push_back({v[1].first, mini});
    mini++;
  }
  long long mx, my, d = 1000000;
  for (auto x : chk) {
    long long tem = abs(x3 - x.first) + abs(y3 - x.second);
    d = min(tem, d);
    if (d == tem) {
      mx = x.first;
      my = x.second;
    }
  }
  long long ans =
      abs(v[1].second - v[0].second) + abs(v[1].first - v[0].first) + 1;
  ans += (abs(x3 - mx) + abs(y3 - my));
  cout << ans << "\n";
  path(x1, y1, mx, my, 0);
  path(mx, my, x2, y2, 1);
  path(mx, my, x3, y3, 1);
  cout << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  for (long long i = 0; i < t; i++) solve();
  return 0;
}
