#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  int x1, x2, x3, y1, y2, y3, dx, dy;
  scanf("%d%d%d%d%d%d", &x1, &y1, &x2, &y2, &x3, &y3);
  dx = max(abs(x2 - x1), max(abs(x3 - x1), abs(x3 - x2)));
  dy = max(abs(y2 - y1), max(abs(y3 - y1), abs(y3 - y2)));
  cout << dx + dy + 1 << endl;
  vector<pair<int, int>> a(3);
  a[0].first = x1;
  a[0].second = y1;
  a[1].first = x2;
  a[1].second = y2;
  a[2].first = x3;
  a[2].second = y3;
  sort(a.begin(), a.end());
  x1 = a[0].first;
  y1 = a[0].second;
  x2 = a[1].first;
  y2 = a[1].second;
  x3 = a[2].first;
  y3 = a[2].second;
  if (y1 <= y2 && y2 <= y3) {
    int i;
    for (i = x1; i <= x2; i++) cout << i << " " << y1 << endl;
    for (i = y1 + 1; i <= y3; i++) cout << x2 << " " << i << endl;
    for (i = x2 + 1; i <= x3; i++) cout << i << " " << y3 << endl;
  } else if (y3 <= y2 && y2 <= y1) {
    int i;
    for (i = x1; i <= x2; i++) cout << i << " " << y1 << endl;
    for (i = y1 - 1; i >= y3; i--) cout << x2 << " " << i << endl;
    for (i = x2 + 1; i <= x3; i++) cout << i << " " << y3 << endl;
  } else if (y1 <= y3 && y3 <= y2) {
    int i;
    for (i = x1; i <= x2; i++) cout << i << " " << y1 << endl;
    for (i = y1 + 1; i <= y2; i++) cout << x2 << " " << i << endl;
    for (i = x2 + 1; i <= x3; i++) cout << i << " " << y3 << endl;
  } else if (y3 < y1 && y1 < y2) {
    int i;
    for (i = x1; i <= x2; i++) cout << i << " " << y1 << endl;
    for (i = y1 + 1; i <= y2; i++) cout << x2 << " " << i << endl;
    for (i = x2 + 1; i <= x3; i++) cout << i << " " << y1 << endl;
    for (i = y1 - 1; i >= y3; i--) cout << x3 << " " << i << endl;
  } else if (y2 <= y3 && y3 <= y1) {
    int i;
    for (i = x1; i <= x2; i++) cout << i << " " << y1 << endl;
    for (i = y1 - 1; i >= y2; i--) cout << x2 << " " << i << endl;
    for (i = x2 + 1; i <= x3; i++) cout << i << " " << y3 << endl;
  } else if (y2 < y1 && y1 < y3) {
    int i;
    for (i = x1; i <= x2; i++) cout << i << " " << y1 << endl;
    for (i = y1 - 1; i >= y2; i--) cout << x2 << " " << i << endl;
    for (i = y1 + 1; i <= y3; i++) cout << x2 << " " << i << endl;
    for (i = x2 + 1; i <= x3; i++) cout << i << " " << y3 << endl;
  }
  return 0;
}
