diff --git a/work/week12/starting_point/CMakeLists.txt b/work/week12/starting_point/CMakeLists.txt
index c5359c4..e9c16a2 100644
--- a/work/week12/starting_point/CMakeLists.txt
+++ b/work/week12/starting_point/CMakeLists.txt
@@ -1,70 +1,71 @@
 cmake_minimum_required (VERSION 3.1)
 project (Particles)
+cmake_policy(VERSION 3.3)
 
 set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${PROJECT_SOURCE_DIR}/cmake")
 
 ################################################################
 # libpart
 ################################################################
 
 add_library(part
   compute_boundary.cc
   compute_verlet_integration.cc 
   particle.cc 
   planet.cc
   compute_gravity.cc 
   csv_reader.cc 
   particles_factory_interface.cc 
   planets_factory.cc 
   compute_contact.cc 
   compute_kinetic_energy.cc 
   csv_writer.cc 
   system.cc 
   compute_energy.cc 
   compute_potential_energy.cc 
   ping_pong_ball.cc
   material_point.cc 
   system_evolution.cc 
   ping_pong_balls_factory.cc 
   compute_interaction.cc
   compute_temperature.cc
   material_points_factory.cc 
   )
 
 add_executable(particles main.cc)
 target_link_libraries(particles part)
 
 ################################################################
 # Google test
 ################################################################
 
 
 include(GoogleTest)
 enable_testing()
 find_package(GTest)
 if (GTEST_FOUND)
 include_directories(${GTEST_INCLUDE_DIRS})
 add_executable(test_kepler test_kepler.cc)
 add_executable(test_fft test_fft.cc)
 target_link_libraries(test_kepler part ${GTEST_BOTH_LIBRARIES} pthread)
 target_link_libraries(test_fft part ${GTEST_BOTH_LIBRARIES} ${FFTW_LIBRARIES} pthread)
 gtest_discover_tests(test_kepler)
 gtest_discover_tests(test_fft)
 endif()
 
 ################################################################
 # Doxygen
 ################################################################
 
 find_package(Doxygen)
 if (DOXYGEN_FOUND)
 
 # to set other options, read: https://cmake.org/cmake/help/v3.9/module/FindDoxygen.html
 doxygen_add_docs(
     doxygen
     ${PROJECT_SOURCE_DIR}
     COMMENT "Generate html pages"
 )
 add_custom_target(doc DEPENDS doxygen)
 endif(DOXYGEN_FOUND)