diff --git a/exercise/01/animal.cpp b/exercise/01/animal.cpp
new file mode 100644
index 0000000..b581a6f
--- /dev/null
+++ b/exercise/01/animal.cpp
@@ -0,0 +1,65 @@
+#include "animal.h"
+
+unsigned insect::legs() const
+{
+	return legCount;
+}
+
+std::wstring cockroach::species() const
+{
+	return speciesName;
+}
+
+unsigned bird::legs() const
+{
+	return legCount;
+
+}
+
+std::wstring sparrow::species() const
+{
+	return speciesName;
+}
+
+unsigned spider::legs() const
+{
+	return legCount;
+
+}
+
+std::wstring tarantula::species() const
+{
+	return speciesName;
+}
+
+std::wstring leg_counter::add_animal(std::unique_ptr<animal> animal)
+{
+	animalCount += animal->legs();
+	return animal->species();
+}
+
+unsigned leg_counter::legs() const
+{
+	return animalCount;
+}
+
+
+enum Animals { Cockroach = 1, Sparrow = 2, Tarantula = 3 };
+
+std::unique_ptr<animal> animal_factory(int num)
+{
+	if (num == Animals::Cockroach)
+	{
+		return std::make_unique<cockroach>();
+	}
+	if (num == Animals::Sparrow)
+	{
+		return std::make_unique<sparrow>();
+	}
+	if (num == Animals::Tarantula)
+	{
+		return std::make_unique<tarantula>();
+	}
+
+	return nullptr;
+}
\ No newline at end of file
diff --git a/exercise/01/animal.h b/exercise/01/animal.h
new file mode 100644
index 0000000..1ca3dce
--- /dev/null
+++ b/exercise/01/animal.h
@@ -0,0 +1,69 @@
+#pragma once
+#include <string>
+
+class animal
+{
+public:
+	virtual ~animal() = default;
+	virtual std::wstring species() const = 0;
+	virtual unsigned legs() const = 0;
+};
+
+class insect : public animal
+{
+public:
+	unsigned legs() const override;
+protected:
+	static const unsigned legCount = 6;
+};
+
+class cockroach : public insect
+{
+public:
+	std::wstring species() const override;
+protected:
+	const std::wstring speciesName = L"cockroach";
+};
+
+class bird : public animal
+{
+public:
+	unsigned legs() const override;
+protected:
+	static const unsigned legCount = 2;
+};
+
+class sparrow : public bird
+{
+public:
+	std::wstring species() const override;
+protected:
+	const std::wstring speciesName = L"sparrow";
+};
+
+class spider : public animal
+{
+public:
+	unsigned legs() const override;
+protected:
+	static const unsigned legCount = 8;
+};
+
+class tarantula : public spider
+{
+public:
+	std::wstring species() const override;
+protected:
+	const std::wstring speciesName = L"tarantula";
+};
+
+class leg_counter
+{
+public:
+	std::wstring add_animal(std::unique_ptr<animal>);
+	unsigned legs() const;
+private:
+	unsigned animalCount = 0;
+};
+
+std::unique_ptr<animal> animal_factory(int num);
\ No newline at end of file
diff --git a/exercise/01/animals.vcxproj b/exercise/01/animals.vcxproj
index 0c14cbf..42f52e7 100644
--- a/exercise/01/animals.vcxproj
+++ b/exercise/01/animals.vcxproj
@@ -82,13 +82,13 @@
       <AdditionalLibraryDirectories>$(VCInstallDir)UnitTest\lib;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
     </Link>
   </ItemDefinitionGroup>
-  <ItemGroup>
-    <ClInclude Include="animal.h" />
-  </ItemGroup>
   <ItemGroup>
     <ClCompile Include="animal.cpp" />
     <ClCompile Include="test.cpp" />
   </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="animal.h" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
diff --git a/exercise/01/animals.vcxproj.filters b/exercise/01/animals.vcxproj.filters
index ad4d9ab..d9e01c3 100644
--- a/exercise/01/animals.vcxproj.filters
+++ b/exercise/01/animals.vcxproj.filters
@@ -1,24 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
-    <Filter Include="src">
-      <UniqueIdentifier>{f2ada0ee-91e7-4bbd-b33d-837567340243}</UniqueIdentifier>
-    </Filter>
     <Filter Include="test">
       <UniqueIdentifier>{3cc0fd48-6585-4969-94bd-406daa5f786b}</UniqueIdentifier>
     </Filter>
+    <Filter Include="src">
+      <UniqueIdentifier>{5bbc7edf-5c58-4e05-91a8-f558bea5d453}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="test.cpp">
       <Filter>test</Filter>
     </ClCompile>
-    <ClCompile Include="animal.cpp">
-      <Filter>src</Filter>
-    </ClCompile>
+    <ClCompile Include="animal.cpp" />
   </ItemGroup>
   <ItemGroup>
-    <ClInclude Include="animal.h">
-      <Filter>src</Filter>
-    </ClInclude>
+    <ClInclude Include="animal.h" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/exercise/01/animals.vcxproj.user b/exercise/01/animals.vcxproj.user
new file mode 100644
index 0000000..be25078
--- /dev/null
+++ b/exercise/01/animals.vcxproj.user
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup />
+</Project>
\ No newline at end of file