`end_of_day4.tar.gz` is our `work` directory at the end of day4 (Thursday). This is where we will start from Friday. You can extract it by: tar -xzvf end_of_day4.tar.gz then go to the build directory, configure, build and execute: cd end_of_day4/build/ cmake ../ -DGeant4_DIR=$G4INSTALL/lib64/cmake/Geant4 make ./yourmain