diff --git a/homework4/starting_point/.idea/workspace.xml b/homework4/starting_point/.idea/workspace.xml
index afeae20..0a57bb3 100644
--- a/homework4/starting_point/.idea/workspace.xml
+++ b/homework4/starting_point/.idea/workspace.xml
@@ -1,448 +1,448 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
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     <generated>
       <config projectName="Particles" targetName="test_kepler" />
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       <usages-collector id="statistics.file.extensions.edit">
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       <usages-collector id="statistics.file.types.edit">
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       <configuration name="test_fft" configurationId="CMakeGoogleTestRunConfigurationType" />
     </history-entry>
   </component>
   <component name="TimeTrackingManager">
-    <option name="totallyTimeSpent" value="20620000" />
+    <option name="totallyTimeSpent" value="21106000" />
   </component>
   <component name="ToolWindowManager">
     <frame x="1" y="23" width="1269" height="716" extended-state="0" />
     <editor active="true" />
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       <provider selected="true" editor-type-id="text-editor">
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             <element signature="e#0#29#0" expanded="true" />
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+        <state relative-caret-position="300">
+          <caret line="52" column="4" lean-forward="true" selection-start-line="52" selection-start-column="4" selection-end-line="52" selection-end-column="4" />
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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 eeb1550..4fba865 100644
--- a/homework4/starting_point/main.py
+++ b/homework4/starting_point/main.py
@@ -1,63 +1,62 @@
 #!/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()
 
 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()
diff --git a/homework4/starting_point/py_part.cpp b/homework4/starting_point/py_part.cpp
index 4576465..d818973 100644
--- a/homework4/starting_point/py_part.cpp
+++ b/homework4/starting_point/py_part.cpp
@@ -1,54 +1,56 @@
 #include <functional>
 #include <iostream>
 #include <pybind11/pybind11.h>
-#include "particles_factory_interface.hh"
 #include "planets_factory.hh"
 #include "ping_pong_balls_factory.hh"
 #include "material_points_factory.hh"
+#include "csv_writer.hh"
 
 namespace py = pybind11;
 
 PYBIND11_MODULE(pypart, m) {
     m.doc() = "pybind particle plugin"; // optional docstring
 
     // wrap the class
     py::class_<ParticlesFactoryInterface>(m, "ParticlesFactoryInterface")
             .def("getInstance", &ParticlesFactoryInterface::getInstance,
                     py::return_value_policy::reference);
 
     py::class_<PingPongBallsFactory, ParticlesFactoryInterface>(m, "PingPongBallsFactory")
             .def("getInstance", &PingPongBallsFactory::getInstance,
                     py::return_value_policy::reference)
             .def("createSimulation", &PingPongBallsFactory::createSimulation,
                  py::return_value_policy::reference);
 
     py::class_<PlanetsFactory, ParticlesFactoryInterface>(m, "PlanetsFactory")
             .def("getInstance", &PlanetsFactory::getInstance,
                     py::return_value_policy::reference)
             .def("createSimulation", &PlanetsFactory::createSimulation,
                  py::return_value_policy::reference);
 
     py::class_<MaterialPointsFactory, ParticlesFactoryInterface>(m, "MaterialPointsFactory")
             .def("getInstance", &MaterialPointsFactory::getInstance,
                     py::return_value_policy::reference)
             .def("createSimulation",
                     (SystemEvolution & (MaterialPointsFactory::*)(const std::string &, Real))
                     &MaterialPointsFactory::createSimulation, py::return_value_policy::reference
             )
             .def("createSimulation", py::overload_cast<const std::string&, Real, py::function>
                     (&MaterialPointsFactory::createSimulation<py::function>),
                     py::return_value_policy::reference);
 
     py::class_<SystemEvolution>(m, "SystemEvolution")
             .def("setNSteps", &SystemEvolution::setNSteps)
             .def("setDumpFreq", &SystemEvolution::setDumpFreq)
             .def("evolve", &SystemEvolution::evolve)
             .def("getSystem", &SystemEvolution::getSystem,
                  py::return_value_policy::reference);
 
     py::class_<CsvWriter>(m, "CsvWriter")
             .def(py::init<const std::string&>())
-            .def("write", &CsvWriter::write)
+            .def("write", &CsvWriter::write);
+
+    py::class_<System>(m, "System");
 }