a) Clone your own summerschool repository also to Puhti. The system default git is pretty old, so first load a module for more recent git with module load git. In Puhti, go to the folder unix-version-control/ and try to compile the prog.cpp file using the make command (make prog).
b) See the batch job script job_script.sh and add the missing srun command to execute the program that you just compiled. Run the program using 24 cores! Send your job to the queue with the command sbatch job_script.sh and check the results.