I am currently trying to run a program in GPS and this is my first time trying to use Ada and don't quite understand some things to it. I have some code that was told was supposed to run but can't seem to get it running. When I try to compile it or run the code, I keep getting an error message: "end of file expected. file can only be one compilation unit." I also included a photo to help show the problem. I'd appreciate any tips or hints on how to solve this please!

enter image description here