How to only display a URL link to an uploaded file if only one of the four is actually uploaded in the form?

How to only display a URL link to an uploaded file if only one of the four is actually uploaded in the form?

I have a form with 4 optional image uploaders. When the form is submitted it emails the input of the form fields and 4 links to the uploaded files. What is the script to only display the link in the sent email if for instance only 2 images were uploaded instead of 4?