How to merge multiple PowerPoint ppt/pptx presentation files into one single file automatically?

I wanted to merge several PowerPoint pptx files into a single (new) presentation automatically

How-I-fixed-it:

I found a PowerShell Script here to get this done (requires PowerPoint to be installed on the computer executing the script):
https://gallery.technet.microsoft.com/office/Merge-multiple-PowerPoint-49139f2c/view/

At the end of the script there are two examples showing the usage of the script.

Worked well for me to merge 52 presenations into a single one with 800 slides.