diff --git a/homework4/starting_point/.idea/workspace.xml b/homework4/starting_point/.idea/workspace.xml
index 4e7b6fb..fed343f 100644
--- a/homework4/starting_point/.idea/workspace.xml
+++ b/homework4/starting_point/.idea/workspace.xml
@@ -1,400 +1,449 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="CMakeRunConfigurationManager" shouldGenerate="true" shouldDeleteObsolete="true" buildAllGenerated="true">
     <generated>
       <config projectName="Particles" targetName="test_kepler" />
       <config projectName="Particles" targetName="part" />
       <config projectName="Particles" targetName="test_fft" />
       <config projectName="Particles" targetName="particles" />
     </generated>
   </component>
   <component name="CMakeSettings">
     <configurations>
       <configuration PROFILE_NAME="Debug" CONFIG_NAME="Debug" />
     </configurations>
   </component>
   <component name="ChangeListManager">
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-      <change beforePath="$PROJECT_DIR$/py_part.cpp" beforeDir="false" afterPath="$PROJECT_DIR$/py_part.cpp" afterDir="false" />
-    </list>
+    <list default="true" id="b4e9d45a-71a7-4f96-94b1-4bcb4ac5e568" name="Default Changelist" comment="" />
     <ignored path="$PROJECT_DIR$/cmake-build-debug/" />
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           <entry key="project.opened" value="1" />
         </counts>
       </usages-collector>
       <usages-collector id="statistics.file.extensions.open">
         <counts>
-          <entry key="cc" value="8" />
+          <entry key="cc" value="11" />
           <entry key="cpp" value="1" />
           <entry key="hh" value="11" />
           <entry key="txt" value="1" />
         </counts>
       </usages-collector>
       <usages-collector id="statistics.file.types.open">
         <counts>
           <entry key="CMakeLists.txt" value="1" />
-          <entry key="ObjectiveC" value="20" />
+          <entry key="ObjectiveC" value="23" />
         </counts>
       </usages-collector>
       <usages-collector id="statistics.file.extensions.edit">
         <counts>
           <entry key="cpp" value="176" />
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             </state>
           </provider>
         </entry>
       </file>
-      <file pinned="false" current-in-tab="true">
+      <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/py_part.cpp">
           <provider selected="true" editor-type-id="text-editor">
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-              <caret line="36" column="78" lean-forward="true" selection-start-line="36" selection-start-column="78" selection-end-line="36" selection-end-column="78" />
+            <state relative-caret-position="202">
+              <caret line="33" column="57" selection-start-line="33" selection-start-column="57" selection-end-line="33" selection-end-column="57" />
               <folding>
                 <element signature="e#0#21#0" expanded="true" />
               </folding>
             </state>
           </provider>
         </entry>
       </file>
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/csv_writer.cc">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="-51">
+              <folding>
+                <element signature="e#0#24#0" expanded="true" />
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+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/system_evolution.cc">
+          <provider selected="true" editor-type-id="text-editor">
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+              <folding>
+                <element signature="e#0#30#0" expanded="true" />
+              </folding>
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file pinned="false" current-in-tab="true">
+        <entry file="file://$PROJECT_DIR$/main.cc">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="335">
+              <caret line="58" column="25" selection-start-line="58" selection-start-column="25" selection-end-line="58" selection-end-column="25" />
+              <folding>
+                <element signature="e#0#29#0" expanded="true" />
+              </folding>
+            </state>
+          </provider>
+        </entry>
+      </file>
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/material_points_factory.hh">
           <provider selected="true" editor-type-id="text-editor">
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     <option name="CHANGED_PATHS">
       <list>
         <option value="$PROJECT_DIR$/CMakeLists.txt" />
         <option value="$PROJECT_DIR$/py_part.cpp" />
       </list>
     </option>
   </component>
   <component name="JsBuildToolGruntFileManager" detection-done="true" sorting="DEFINITION_ORDER" />
   <component name="JsBuildToolPackageJson" detection-done="true" sorting="DEFINITION_ORDER" />
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     <detection-done>true</detection-done>
     <sorting>DEFINITION_ORDER</sorting>
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     <option name="y" value="23" />
     <option name="width" value="1269" />
     <option name="height" value="716" />
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   <component name="ProjectView">
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     <panes>
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         <subPane>
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               <item name="Particles" type="b2602c69:ProjectViewProjectNode" />
               <item name="starting_point" type="462c0819:PsiDirectoryNode" />
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           <select />
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     <property name="settings.editor.selected.configurable" value="editor.preferences.import" />
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   <component name="RunDashboard">
     <option name="ruleStates">
       <list>
         <RuleState>
           <option name="name" value="ConfigurationTypeDashboardGroupingRule" />
         </RuleState>
         <RuleState>
           <option name="name" value="StatusDashboardGroupingRule" />
         </RuleState>
       </list>
     </option>
   </component>
   <component name="RunManager" selected="Application.particles">
     <configuration name="test_fft" type="CMakeGoogleTestRunConfigurationType" factoryName="Google Test" PASS_PARENT_ENVS_2="true" PROJECT_NAME="Particles" TARGET_NAME="test_fft" CONFIG_NAME="Debug" RUN_TARGET_PROJECT_NAME="Particles" RUN_TARGET_NAME="test_fft" TEST_MODE="SUITE_TEST">
       <method v="2">
         <option name="com.jetbrains.cidr.execution.CidrBuildBeforeRunTaskProvider$BuildBeforeRunTask" enabled="true" />
       </method>
     </configuration>
     <configuration name="test_kepler" type="CMakeGoogleTestRunConfigurationType" factoryName="Google Test" PASS_PARENT_ENVS_2="true" PROJECT_NAME="Particles" TARGET_NAME="test_kepler" CONFIG_NAME="Debug" RUN_TARGET_PROJECT_NAME="Particles" RUN_TARGET_NAME="test_kepler" TEST_MODE="SUITE_TEST">
       <method v="2">
         <option name="com.jetbrains.cidr.execution.CidrBuildBeforeRunTaskProvider$BuildBeforeRunTask" enabled="true" />
       </method>
     </configuration>
     <configuration name="Build All" type="CMakeRunConfiguration" factoryName="Application" PASS_PARENT_ENVS_2="true" CONFIG_NAME="Debug" EXPLICIT_BUILD_TARGET_NAME="all">
       <method v="2">
         <option name="com.jetbrains.cidr.execution.CidrBuildBeforeRunTaskProvider$BuildBeforeRunTask" enabled="true" />
       </method>
     </configuration>
     <configuration name="part" type="CMakeRunConfiguration" factoryName="Application" PASS_PARENT_ENVS_2="true" PROJECT_NAME="Particles" TARGET_NAME="part" CONFIG_NAME="Debug">
       <method v="2">
         <option name="com.jetbrains.cidr.execution.CidrBuildBeforeRunTaskProvider$BuildBeforeRunTask" enabled="true" />
       </method>
     </configuration>
     <configuration name="particles" type="CMakeRunConfiguration" factoryName="Application" PASS_PARENT_ENVS_2="true" PROJECT_NAME="Particles" TARGET_NAME="particles" CONFIG_NAME="Debug" RUN_TARGET_PROJECT_NAME="Particles" RUN_TARGET_NAME="particles">
       <method v="2">
         <option name="com.jetbrains.cidr.execution.CidrBuildBeforeRunTaskProvider$BuildBeforeRunTask" enabled="true" />
       </method>
     </configuration>
     <list>
       <item itemvalue="Application.Build All" />
       <item itemvalue="Application.part" />
       <item itemvalue="Application.particles" />
       <item itemvalue="Google Test.test_fft" />
       <item itemvalue="Google Test.test_kepler" />
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   <component name="SvnConfiguration">
     <configuration />
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   <component name="TaskManager">
     <task active="true" id="Default" summary="Default task">
       <changelist id="b4e9d45a-71a7-4f96-94b1-4bcb4ac5e568" name="Default Changelist" comment="" />
       <created>1545641844292</created>
       <option name="number" value="Default" />
       <option name="presentableId" value="Default" />
       <updated>1545641844292</updated>
       <workItem from="1545641847884" duration="14534000" />
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     <servers />
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   <component name="TestHistory">
     <history-entry file="test_fft - 2018.12.24 at 10h 50m 19s.xml">
       <configuration name="test_fft" configurationId="CMakeGoogleTestRunConfigurationType" />
     </history-entry>
     <history-entry file="test_fft - 2018.12.24 at 10h 59m 02s.xml">
       <configuration name="test_fft" configurationId="CMakeGoogleTestRunConfigurationType" />
     </history-entry>
     <history-entry file="test_fft - 2018.12.24 at 11h 03m 49s.xml">
       <configuration name="test_fft" configurationId="CMakeGoogleTestRunConfigurationType" />
     </history-entry>
   </component>
   <component name="TimeTrackingManager">
-    <option name="totallyTimeSpent" value="17648000" />
+    <option name="totallyTimeSpent" value="18633000" />
   </component>
   <component name="ToolWindowManager">
     <frame x="1" y="23" width="1269" height="716" extended-state="0" />
     <editor active="true" />
     <layout>
       <window_info id="Favorites" side_tool="true" />
       <window_info active="true" content_ui="combo" id="Project" order="0" visible="true" weight="0.24938875" />
       <window_info id="Structure" order="1" side_tool="true" weight="0.25" />
       <window_info anchor="bottom" id="Database Changes" show_stripe_button="false" />
       <window_info anchor="bottom" id="Version Control" />
       <window_info anchor="bottom" id="Messages" weight="0.32852563" />
       <window_info anchor="bottom" id="Terminal" />
       <window_info anchor="bottom" id="Event Log" side_tool="true" />
       <window_info anchor="bottom" id="CMake" weight="0.32852563" />
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       <window_info anchor="bottom" id="Find" order="1" />
       <window_info anchor="bottom" id="Run" order="2" visible="true" weight="0.32852563" />
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       <window_info anchor="bottom" id="Cvs" order="4" weight="0.25" />
       <window_info anchor="bottom" id="Inspection" order="5" weight="0.4" />
       <window_info anchor="bottom" id="TODO" order="6" />
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       <window_info anchor="right" id="Commander" internal_type="SLIDING" order="0" type="SLIDING" weight="0.4" />
       <window_info anchor="right" id="Ant Build" order="1" weight="0.25" />
       <window_info anchor="right" content_ui="combo" id="Hierarchy" order="2" weight="0.25" />
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   <component name="TypeScriptGeneratedFilesManager">
     <option name="version" value="1" />
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   <component name="VcsContentAnnotationSettings">
     <option name="myLimit" value="2678400000" />
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   <component name="editorHistoryManager">
     <entry file="file://$PROJECT_DIR$/test_fft.cc">
       <provider selected="true" editor-type-id="text-editor">
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     <entry file="file://$PROJECT_DIR$/compute_temperature.cc">
       <provider selected="true" editor-type-id="text-editor">
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           <folding>
             <element signature="e#0#33#0" expanded="true" />
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     <entry file="file://$PROJECT_DIR$/fft.hh">
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     <entry file="file://$PROJECT_DIR$/compute_temperature.hh">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="-104" />
       </provider>
     </entry>
     <entry file="file://$PROJECT_DIR$/particles_factory_interface.cc">
       <provider selected="true" editor-type-id="text-editor">
         <state>
           <folding>
             <element signature="e#0#41#0" expanded="true" />
           </folding>
         </state>
       </provider>
     </entry>
     <entry file="file://$PROJECT_DIR$/ping_pong_balls_factory.hh">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="120">
           <caret line="9" column="6" lean-forward="true" selection-start-line="9" selection-start-column="6" selection-end-line="9" selection-end-column="26" />
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     <entry file="file://$PROJECT_DIR$/planets_factory.cc">
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-          <caret line="36" column="78" lean-forward="true" selection-start-line="36" selection-start-column="78" selection-end-line="36" selection-end-column="78" />
+        <state relative-caret-position="202">
+          <caret line="33" column="57" selection-start-line="33" selection-start-column="57" selection-end-line="33" selection-end-column="57" />
           <folding>
             <element signature="e#0#21#0" expanded="true" />
           </folding>
         </state>
       </provider>
     </entry>
+    <entry file="file://$PROJECT_DIR$/csv_writer.cc">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="-51">
+          <folding>
+            <element signature="e#0#24#0" expanded="true" />
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+        </state>
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+    </entry>
+    <entry file="file://$PROJECT_DIR$/system_evolution.cc">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="-57">
+          <folding>
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+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/main.cc">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="335">
+          <caret line="58" column="25" selection-start-line="58" selection-start-column="25" selection-end-line="58" selection-end-column="25" />
+          <folding>
+            <element signature="e#0#29#0" expanded="true" />
+          </folding>
+        </state>
+      </provider>
+    </entry>
   </component>
   <component name="masterDetails">
     <states>
       <state key="ScopeChooserConfigurable.UI">
         <settings>
           <splitter-proportions>
             <option name="proportions">
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 </project>
\ No newline at end of file
diff --git a/homework4/starting_point/main.py b/homework4/starting_point/main.py
index 24f60d4..eeb1550 100644
--- a/homework4/starting_point/main.py
+++ b/homework4/starting_point/main.py
@@ -1,60 +1,63 @@
 #!/bin/env python3
 
 import sys
 import argparse
 from pypart import MaterialPointsFactory, ParticlesFactoryInterface
 from pypart import PingPongBallsFactory, PlanetsFactory
 from pypart import CsvWriter
 from pypart import ComputeTemperature
+from pypart import SystemEvolution
 # help(pypart)
 
 parser = argparse.ArgumentParser(description='Particles code')
 parser.add_argument('nsteps', type=int,
                     help='specify the number of steps to perform')
 parser.add_argument('freq', type=int,
                     help='specify the frequency for dumps')
 parser.add_argument('filename', type=str,
                     help='start/input filename')
 parser.add_argument('particle_type', type=str,
                     help='particle type')
 parser.add_argument('timestep', type=float,
                     help='timestep')
 
 args = parser.parse_args()
 nsteps = args.nsteps
 freq = args.freq
 filename = args.filename
 particle_type = args.particle_type
 timestep = args.timestep
 
 if particle_type == "planet":
     PlanetsFactory.getInstance()
 elif particle_type == "ping_pong":
     PingPongBallsFactory.getInstance()
 elif particle_type == "material_point":
     MaterialPointsFactory.getInstance()
 else:
     print("Unknown particle type: ", particle_type)
     sys.exit(-1)
 
 factory = ParticlesFactoryInterface.getInstance()
 
-
-def createComputes(self, timestep):
-    compute_temp = ComputeTemperature()
-    compute_temp.conductivity = 1
-    compute_temp.L = 2
-    compute_temp.capacity = 1
-    compute_temp.density = 1
-    compute_temp.deltat = 1
-    self.system_evolution.addCompute(compute_temp)
-
-
-evol = factory.createSimulation(filename, timestep, createComputes)
+if particle_type == "material_point":
+    def createComputes(self, timestep):
+        compute_temp = ComputeTemperature()
+        compute_temp.conductivity = 1
+        compute_temp.L = 2
+        compute_temp.capacity = 1
+        compute_temp.density = 1
+        compute_temp.deltat = 1
+        self.system_evolution.addCompute(compute_temp)
+    
+    evol = factory.createSimulation(filename, timestep, createComputes)
+    
+else:
+    evol = factory.createSimulation(filename, timestep)
 
 dumper = CsvWriter("init.csv")
 dumper.write(evol.getSystem())
 
 evol.setNSteps(nsteps)
 evol.setDumpFreq(freq)
 evol.evolve()