#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int x[3], y[3];
  int a, b;
  vector<pair<int, int>> v;
  for (int i = 0; i < 3; ++i) {
    scanf("%d %d", &a, &b);
    v.push_back(make_pair(a, b));
  }
  sort(v.begin(), v.end());
  for (int i = 0; i < 3; ++i) {
    x[i] = v[i].first;
    y[i] = v[i].second;
  }
  int suma = 0;
  suma += x[1] - x[0] + abs(y[1] - y[0]);
  if (y[2] < y[1] && y[2] < y[0]) {
    suma += min(y[0], y[1]) - y[2] + x[2] - x[1];
  } else if (y[2] > y[0] && y[2] > y[1]) {
    suma += y[2] - max(y[0], y[1]) + x[2] - x[1];
  } else {
    suma += x[2] - x[1];
  }
  cout << suma + 1 << endl;
  for (int i = x[0]; i <= x[1]; ++i) {
    cout << i << " " << y[0] << endl;
  }
  if (y[1] > y[0]) {
    for (int i = y[0] + 1; i <= y[1]; ++i) {
      cout << x[1] << " " << i << endl;
    }
  } else {
    for (int i = y[0] - 1; i >= y[1]; --i) {
      cout << x[1] << " " << i << endl;
    }
  }
  if (y[2] <= y[1] && y[2] <= y[0]) {
    for (int i = min(y[0], y[1]) - 1; i >= y[2]; --i) {
      cout << x[1] << " " << i << endl;
    }
  }
  if (y[2] > y[1] && y[2] > y[0]) {
    for (int i = max(y[0], y[1]) + 1; i <= y[2]; ++i) {
      cout << x[1] << " " << i << endl;
    }
  }
  for (int i = x[1] + 1; i <= x[2]; ++i) {
    cout << i << " " << y[2] << endl;
  }
  return 0;
}
