Odd Request: Shrinking PowerPoint pdf slides

I know this is an odd request, but I am not sure how to do this. I have about 218 PowerPoint slides in pdf format. I'm looking to shrink them down and have them all be on 2 pages (1 front and back sheet). I would like to have at least the first 200 of them, so at least 100 on each side of a piece of paper. I also need them clear enough so that I can print them out and still read them, even if I have to be really close to the paper. I have tried several methods and can't get it to be just right, it had way too much white space and was too blurry. I'm hoping that someone with photoshop can help with this.