Join Pdf into one file

The work consists of merging PDF files into a single file with the following scheme:

1 - Take an image from the dinosaur folder
2 - insert the blank.PDF file
3 - Take an image from the mazes folder
4 - insert the blank.PDF file
5 - Take an image from the dot to dot folder
6 - insert the blank.Pdf file
7 - insert the file drawn free.Pdf
8 - insert the blank.PDF file

Repeat the above diagram until you have finished inserting all the images in the dinosaurs - mazes - dot to dot folders.

The dinosaurs and mazes folder contains 41 images, while the dot to dot folder contains 50 images. When the images of the dinosaurs and mazes folder are finished continue with steps 5 - 6 - 7 - 8 until you finish the images contained in the dot to dot folder.