#include <bits/stdc++.h>
using namespace std;
int main() {
  int x[3];
  int y[3];
  cin >> x[0] >> y[0] >> x[1] >> y[1] >> x[2] >> y[2];
  int vis[10000];
  vis[x[0]] = y[0];
  vis[x[1]] = y[1];
  vis[x[2]] = y[2];
  sort(x, x + 3);
  sort(y, y + 3);
  cout << x[2] - x[0] + y[2] - y[0] + 1 << endl;
  for (int i = x[0]; i < x[1]; i++) {
    cout << i << " " << vis[x[0]] << endl;
  }
  for (int i = x[2]; x[1] < i; i--) {
    cout << i << " " << vis[x[2]] << endl;
  }
  for (int i = y[0]; i <= y[2]; i++) {
    cout << x[1] << " " << i << endl;
  }
}
