diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..ce90b2e
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,60 @@
+# Set the minimum required version of CMake
+cmake_minimum_required(VERSION 3.10)
+
+# Set the project name
+project(exercise)
+
+# Set the C++ standard (adjust if needed)
+set(CMAKE_CXX_STANDARD 14)
+
+
+# Part 1
+# Boost libraries
+find_package(Boost 1.71 REQUIRED COMPONENTS filesystem)
+
+# Include Boost headers
+include_directories(${Boost_INCLUDE_DIRS})
+
+# flatset
+set(FLATSET_SOURCES flatset/flatset.cpp)
+
+# Include directories for the flatset module
+include_directories(flatset)
+
+# Part 2
+# deal II
+find_package(deal.II REQUIRED HINTS ${DEAL_II_DIR} 
+             PATHS /usr/lib/cmake/deal.II)
+
+# Add the source file for the Fem class
+set(FEM_SOURCES fem/fem.cpp)
+
+# Include directories for the fem module
+include_directories(fem)
+
+
+# Part 3
+# Filesystem
+set(FILESYSTEM_SOURCES filesystem/filesystem.cpp)
+
+# Include directories for the filesystem module
+include_directories(filesystem)
+
+# Add the source files to the executable
+add_executable(main main.cpp ${FEM_SOURCES} ${FLATSET_SOURCES} ${FILESYSTEM_SOURCES})
+
+# Link Boost Filesystem
+target_link_libraries(main Boost::filesystem)
+
+
+# Link deal.II to the executable
+deal_ii_setup_target(main)
+
+# If you need specific libraries or include directories, add them here:
+# target_include_directories(main PRIVATE /path/to/headers)
+# target_link_libraries(main PRIVATE /path/to/library)
+
+# Optionally set debugging options
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+    message(STATUS "Building in Debug mode")
+endif()
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..20eaece
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,18 @@
+FROM ubuntu:24.04
+
+# apt-get installs basics
+RUN apt-get update 
+RUN apt-get install build-essential cmake unzip wget vim -y
+# boost
+RUN apt-get install libboost-all-dev -y
+# deal II
+RUN apt-get install libdeal.ii-dev -y
+
+
+# no more used, now use mount
+WORKDIR /cmake-exercise
+COPY . /cmake-exercise
+
+# change the encoding of shell to remove '\r'
+RUN sed -i 's/\r$//' build_and_run.sh 
+CMD ["/bin/bash"]
\ No newline at end of file
diff --git a/build_and_run.sh b/build_and_run.sh
index 60c4293..d263094 100755
--- a/build_and_run.sh
+++ b/build_and_run.sh
@@ -1,5 +1,13 @@
+# Normalize line endings to LF
+sed -i 's/\r$//' "$0"
+
 #!/usr/bin/env bash
 
+# Clean up the build directory if it exists
+if [ -d "build" ]; then
+    rm -rf build
+fi
+
 mkdir build
 cd build
 cmake -DCMAKE_BUILD_TYPE=Debug ..
diff --git a/main.cpp b/main.cpp
index 7588360..e183452 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,6 @@
-//#include "fem/fem.hpp"
-//#include "flatset/flatset.hpp"
-//#include "filesystem/filesystem.hpp"
+#include "fem/fem.hpp"
+#include "flatset/flatset.hpp"
+#include "filesystem/filesystem.hpp"
 //#include "yamlParser/yamlParser.hpp"
 #include <iostream>
 
@@ -8,18 +8,18 @@ int main(int argc, char *argv[])
 {
   std::cout << "Let's fight with CMake, Docker, and some dependencies!" << std::endl << std::endl;
 
-  //std::cout << "Solve Poisson problem with FEM using deal.II" << std::endl;
-  //Fem fem;
-  //fem.run();
-  //std::cout << std::endl;
+  std::cout << "Solve Poisson problem with FEM using deal.II" << std::endl;
+  Fem fem;
+  fem.run();
+  std::cout << std::endl;
 
-  //std::cout << "Modify a flat set using boost container" << std::endl;
-  //modifyAndPrintSets();
-  //std::cout << std::endl;
+  std::cout << "Modify a flat set using boost container" << std::endl;
+  modifyAndPrintSets();
+  std::cout << std::endl;
 
-  //std::cout << "Inspect the current directory using boost filesystem" << std::endl;
-  //inspectDirectory();
-  //std::cout << std::endl;
+  std::cout << "Inspect the current directory using boost filesystem" << std::endl;
+  inspectDirectory();
+  std::cout << std::endl;
 
   
   //if ( argc == 2 )