I am building a website using Drupal 7. In my website there is a form for user to add some content.

In the form there is a field of type "Text Field" (core). The "Number of values" for this text field is "unlimited". Thus, when the form appear in the first time,there is only one text field and a button- "add another item". Then users can add more items / fields just by clicking on the button.

I want that always will appear at least 4 fields on the form (and not one).
If the users will want, they will be able to just click on the button and "add another item" (regularly).

How can I can display 4 text fields (and not only one)?