`end_of_day1.tar.gz` is our `work` directory at the end of day1 (Monday). This is where we will start from Tuesday. You can extract it by: tar -xzvf end_of_day1.tar.gz then go to the build directory, configure, build and execute: cd end_of_day1/build/ cmake ../ -DGeant4_DIR=$G4INSTALL/lib64/cmake/ make ./yourmain