diff --git a/C#/forSpbu/Md5Calculator.Tests/GlobalUsings.cs b/C#/forSpbu/Md5Calculator.Tests/GlobalUsings.cs
new file mode 100644
index 0000000..cefced4
--- /dev/null
+++ b/C#/forSpbu/Md5Calculator.Tests/GlobalUsings.cs
@@ -0,0 +1 @@
+global using NUnit.Framework;
\ No newline at end of file
diff --git a/C#/forSpbu/Md5Calculator.Tests/Md5Calculator.Tests.csproj b/C#/forSpbu/Md5Calculator.Tests/Md5Calculator.Tests.csproj
new file mode 100644
index 0000000..a7fc770
--- /dev/null
+++ b/C#/forSpbu/Md5Calculator.Tests/Md5Calculator.Tests.csproj
@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+
+        <IsPackable>false</IsPackable>
+        <IsTestProject>true</IsTestProject>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0"/>
+        <PackageReference Include="NUnit" Version="3.13.3"/>
+        <PackageReference Include="NUnit3TestAdapter" Version="4.2.1"/>
+        <PackageReference Include="NUnit.Analyzers" Version="3.6.1"/>
+        <PackageReference Include="coverlet.collector" Version="6.0.0"/>
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\Md5Calculator\Md5Calculator.csproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/C#/forSpbu/Md5Calculator.Tests/Md5CalculatorTests.cs b/C#/forSpbu/Md5Calculator.Tests/Md5CalculatorTests.cs
new file mode 100644
index 0000000..8eb4b10
--- /dev/null
+++ b/C#/forSpbu/Md5Calculator.Tests/Md5CalculatorTests.cs
@@ -0,0 +1,160 @@
+namespace Md5Calculator.Tests;
+
+public class Md5CalculatorTests
+{
+    private static IEnumerable<Func<string, byte[]>> ComputeInstances()
+    {
+        yield return Md5Calculator.Compute;
+        yield return path => Md5Calculator.ComputeAsync(path).Result;
+    }
+    
+    [Test]
+    public void AsyncEqualsSyncTest()
+    {
+        var dirNames = new []
+        {
+            "./AsyncEqualsSyncTest",
+            "./AsyncEqualsSyncTest/Dir1",
+        };
+        (string path, string data)[] files = new []
+        {
+            ("./AsyncEqualsSyncTest/Dir1/file1.txt", "Asd"),
+            ("./AsyncEqualsSyncTest/file1.txt", "Asd"),
+        };
+        dirNames.AsParallel().ForAll(path => Directory.CreateDirectory(path));
+        files.AsParallel()
+            .ForAll(file => File.WriteAllBytes(file.path, System.Text.Encoding.ASCII.GetBytes(file.data)));
+        
+        Assert.That(Md5Calculator.Compute(dirNames[0]), Is.EqualTo(Md5Calculator.ComputeAsync(dirNames[0]).Result));
+        
+        files.AsParallel()
+            .ForAll(file => File.Delete(file.path));
+        Directory.Delete(dirNames[1]);
+    }
+    
+    [Test, TestCaseSource(nameof(ComputeInstances))]
+    public void RecalculateEqualsTest(Func<string, byte[]> compute)
+    {
+        var dirNames = new []
+        {
+            "./RecalculateEqualsTest",
+            "./RecalculateEqualsTest/Dir1",
+        };
+        (string path, string data)[] files = new []
+        {
+            ("./RecalculateEqualsTest/Dir1/file1.txt", "Asd"),
+            ("./RecalculateEqualsTest/file1.txt", "Asd"),
+        };
+        dirNames.AsParallel().ForAll(path => Directory.CreateDirectory(path));
+        files.AsParallel()
+            .ForAll(file => File.WriteAllBytes(file.path, System.Text.Encoding.ASCII.GetBytes(file.data)));
+        
+        Assert.That(compute(dirNames[0]), Is.EqualTo(compute(dirNames[0])));
+        
+        files.AsParallel()
+            .ForAll(file => File.Delete(file.path));
+        Directory.Delete(dirNames[1]);
+    }
+    
+    [Test, TestCaseSource(nameof(ComputeInstances))]
+    public void FileNameMattersTest(Func<string, byte[]> compute)
+    {
+        var dirNames = new []
+        {
+            "./FileNameMattersTest",
+        };
+        (string path, string data)[] files = new []
+        {
+            ("./FileNameMattersTest/file2.txt", "Asd"),
+            ("./FileNameMattersTest/file1.txt", "Asd"),
+        };
+        dirNames.AsParallel().ForAll(path => Directory.CreateDirectory(path));
+        files.AsParallel()
+            .ForAll(file => File.WriteAllBytes(file.path, System.Text.Encoding.ASCII.GetBytes(file.data)));
+        
+        Assert.That(compute(files[0].path), Is.Not.EqualTo(compute(files[1].path)));
+        
+        files.AsParallel()
+            .ForAll(file => File.Delete(file.path));
+    }
+    
+    [Test, TestCaseSource(nameof(ComputeInstances))]
+    public void DirNameMattersTest(Func<string, byte[]> compute)
+    {
+        var dirNames = new []
+        {
+            "./DirNameMattersTest/Dir1",
+            "./DirNameMattersTest/Dirs5",
+        };
+        (string path, string data)[] files = new []
+        {
+            ("./DirNameMattersTest/Dir1/file1.txt", "Asd"),
+            ("./DirNameMattersTest/Dirs5/file1.txt", "Asd"),
+        };
+        dirNames.AsParallel().ForAll(path => Directory.CreateDirectory(path));
+        files.AsParallel()
+            .ForAll(file => File.WriteAllBytes(file.path, System.Text.Encoding.ASCII.GetBytes(file.data)));
+        
+        Assert.That(compute(dirNames[0]), Is.Not.EqualTo(compute(dirNames[1])));
+        
+        files.AsParallel()
+            .ForAll(file => File.Delete(file.path));
+        dirNames.AsParallel().ForAll(path => Directory.Delete(path));
+    }
+    
+    [Test, TestCaseSource(nameof(ComputeInstances))]
+    public void DirFilesMatterTest(Func<string, byte[]> compute)
+    {
+        var dirNames = new []
+        {
+            "./DirFilesMatterTest/Dir1",
+            "./DirFilesMatterTest/Dir2",
+        };
+        (string path, string data)[] files = new []
+        {
+            ("./DirFilesMatterTest/Dir1/file1.txt", "Asd"),
+            ("./DirFilesMatterTest/Dir2/file1.txt", "Asde"),
+        };
+        dirNames.AsParallel().ForAll(path => Directory.CreateDirectory(path));
+        files.AsParallel()
+            .ForAll(file => File.WriteAllBytes(file.path, System.Text.Encoding.ASCII.GetBytes(file.data)));
+        
+        Assert.That(compute(dirNames[0]), Is.Not.EqualTo(compute(dirNames[1])));
+        
+        files.AsParallel()
+            .ForAll(file => File.Delete(file.path));
+        dirNames.AsParallel().ForAll(path => Directory.Delete(path));
+    }
+    
+    [Test, TestCaseSource(nameof(ComputeInstances))]
+    public void SubDirsMatterTest(Func<string, byte[]> compute)
+    {
+        var dirNames = new []
+        {
+            "./SubDirsMatterTest/Dir1",
+            "./SubDirsMatterTest/Dir2",
+            "./SubDirsMatterTest/Dir1/Dir11",
+            "./SubDirsMatterTest/Dir2/Dir21",
+        };
+        (string path, string data)[] files = new []
+        {
+            ("./SubDirsMatterTest/Dir1/Dir11/file1.txt", "Asd"),
+            ("./SubDirsMatterTest/Dir2/Dir21/file1.txt", "Asde"),
+        };
+        dirNames.AsParallel().ForAll(path => Directory.CreateDirectory(path));
+        files.AsParallel()
+            .ForAll(file => File.WriteAllBytes(file.path, System.Text.Encoding.ASCII.GetBytes(file.data)));
+        
+        Assert.That(compute(dirNames[0]), Is.Not.EqualTo(compute(dirNames[1])));
+        
+        files.AsParallel()
+            .ForAll(file => File.Delete(file.path));
+        Directory.Delete(dirNames[3]);
+        Directory.Delete(dirNames[2]);
+        Directory.Delete(dirNames[1]);
+        Directory.Delete(dirNames[0]);
+
+
+
+    }
+}
\ No newline at end of file
diff --git a/C#/forSpbu/Md5Calculator/CalculatorException.cs b/C#/forSpbu/Md5Calculator/CalculatorException.cs
new file mode 100644
index 0000000..da260d8
--- /dev/null
+++ b/C#/forSpbu/Md5Calculator/CalculatorException.cs
@@ -0,0 +1,22 @@
+namespace Md5Calculator;
+
+/// <summary>
+/// Represents exception thrown in Md5 calculator
+/// </summary>
+public class CalculatorException : ArgumentException
+{
+    /// <summary>
+    /// Creates exception with message
+    /// </summary>
+    /// <param name="message">Exception message</param>
+    public CalculatorException(string message) : base(message)
+    {
+    }
+    
+    /// <summary>
+    /// Creates empty exception
+    /// </summary>
+    public CalculatorException()
+    {
+    }
+}
\ No newline at end of file
diff --git a/C#/forSpbu/Md5Calculator/Md5Calculator.cs b/C#/forSpbu/Md5Calculator/Md5Calculator.cs
new file mode 100644
index 0000000..af3796a
--- /dev/null
+++ b/C#/forSpbu/Md5Calculator/Md5Calculator.cs
@@ -0,0 +1,83 @@
+namespace Md5Calculator;
+
+using System.Security.Cryptography;
+
+/// <summary>
+/// Represents md5 hash calculator
+/// </summary>
+public static class Md5Calculator
+{
+    /// <summary>
+    /// Asynchronously computes md5 hash of given path
+    /// </summary>
+    /// <param name="path">Path to compute</param>
+    /// <returns>Hash as byte array</returns>
+    /// <exception cref="CalculatorException">If given does not exist</exception>
+    public static async Task<byte[]> ComputeAsync(string path)
+    {
+        if (!Directory.Exists(path) && !File.Exists(path))
+        {
+            throw new CalculatorException("Path doesnt exist");
+        }
+        
+        return !Directory.Exists(path) ? await ComputeFileAsync(path) : await ComputeDirAsync(path);
+    }
+    
+    /// <summary>
+    /// Synchronously computes md5 hash of given path
+    /// </summary>
+    /// <param name="path">Path to compute</param>
+    /// <returns>Hash as byte array</returns>
+    /// <exception cref="CalculatorException">If given does not exist</exception>
+    public static byte[] Compute(string path)
+    {
+        if (!Directory.Exists(path) && !File.Exists(path))
+        {
+            throw new CalculatorException("Path doesnt exist");
+        }
+        
+        return !Directory.Exists(path) ? ComputeFile(path) : ComputeDir(path);
+    }
+
+
+    private static async Task<byte[]> ComputeDirAsync(string path)
+    {
+        var fileTasks = Directory.GetFiles(path).Select(ComputeFileAsync);
+
+        var dirTasks = Directory.GetDirectories(path).Select(ComputeDirAsync);
+
+        var tasks = fileTasks.Concat(dirTasks).ToArray();
+        
+        var overallBytes = (await Task.WhenAll(tasks))
+            .SelectMany(byteArray => byteArray)
+            .Concat(ComputeString(new DirectoryInfo(path).Name))
+            .ToArray();
+        return MD5.HashData(overallBytes);
+    }
+    
+    private static byte[] ComputeDir(string path)
+    {
+        var fileBytes = Directory.GetFiles(path).SelectMany(ComputeFile);
+
+        var dirBytes = Directory.GetDirectories(path).SelectMany(ComputeDir);
+        
+        var overallBytes = fileBytes.Concat(dirBytes).Concat(ComputeString(new DirectoryInfo(path).Name)).ToArray();
+        
+        return MD5.HashData(overallBytes);
+    }
+
+    private static async Task<byte[]> ComputeFileAsync(string path)
+    {
+        var byteArray = (await MD5.HashDataAsync(new FileInfo(path).OpenRead())).Concat(ComputeString(new FileInfo(path).Name)).ToArray();
+        return MD5.HashData(byteArray);
+    }
+
+    private static byte[] ComputeFile(string path)
+    {
+        var byteArray = MD5.HashData(new FileInfo(path).OpenRead()).Concat(ComputeString(new FileInfo(path).Name)).ToArray();
+        return MD5.HashData(byteArray);
+    }
+    
+    private static byte[] ComputeString(string @string) => 
+        MD5.HashData(System.Text.Encoding.ASCII.GetBytes(@string));
+}
\ No newline at end of file
diff --git a/C#/forSpbu/Md5Calculator/Md5Calculator.csproj b/C#/forSpbu/Md5Calculator/Md5Calculator.csproj
new file mode 100644
index 0000000..151d8d4
--- /dev/null
+++ b/C#/forSpbu/Md5Calculator/Md5Calculator.csproj
@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net8.0</TargetFramework>
+        <RootNamespace>Md5_calculator</RootNamespace>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+</Project>
diff --git a/C#/forSpbu/Md5Calculator/Program.cs b/C#/forSpbu/Md5Calculator/Program.cs
new file mode 100644
index 0000000..4da3a7c
--- /dev/null
+++ b/C#/forSpbu/Md5Calculator/Program.cs
@@ -0,0 +1,29 @@
+using Md5Calculator;
+using System.Diagnostics;
+
+if (args.Length != 1 || string.IsNullOrEmpty(args[0]))
+{
+    Console.WriteLine("Should be 1 argument with path");
+    return;
+}
+
+try
+{
+    var startTime = Stopwatch.GetTimestamp();
+    var hash = Md5Calculator.Md5Calculator.Compute(args[0]);
+    var endTime = Stopwatch.GetTimestamp();
+    Console.WriteLine($"Single thread: {Convert.ToBase64String(hash)}, {Stopwatch.GetElapsedTime(startTime, endTime)}");
+
+    startTime = Stopwatch.GetTimestamp();
+    hash = await Md5Calculator.Md5Calculator.ComputeAsync(args[0]);
+    endTime = Stopwatch.GetTimestamp();
+    Console.WriteLine($"Multi thread: {Convert.ToBase64String(hash)}, {Stopwatch.GetElapsedTime(startTime, endTime)}");
+}
+catch (CalculatorException e)
+{
+    Console.WriteLine(e.Message);
+}
+catch (IOException e)
+{
+    Console.WriteLine(e.Message);
+}
\ No newline at end of file
diff --git a/C#/forSpbu/forSpbu.sln b/C#/forSpbu/forSpbu.sln
index 527f400..d68c9cf 100644
--- a/C#/forSpbu/forSpbu.sln
+++ b/C#/forSpbu/forSpbu.sln
@@ -10,6 +10,14 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "03.03", "03.03", "{882A9B9C
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "10.03", "10.03", "{EA6FC7D9-BDFB-49CD-AC00-FC5DDC5274B0}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "2023", "2023", "{318796AF-A927-4A13-BAEE-FD13551DE91A}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "30.11", "30.11", "{47EB60F8-9C89-4D13-8243-B77B01A4BA53}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Md5Calculator", "Md5Calculator\Md5Calculator.csproj", "{AA2AD188-B903-46DF-AE43-4769DBF788E9}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Md5Calculator.Tests", "Md5Calculator.Tests\Md5Calculator.Tests.csproj", "{6A71CD77-320C-458F-97B3-BA8F4CB530C6}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -21,12 +29,23 @@ Global
 		{E007586F-9760-4744-BB25-EDEFD6BA860C}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E007586F-9760-4744-BB25-EDEFD6BA860C}.Release|Any CPU.Build.0 = Release|Any CPU
 		{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-       	{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-       	{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-       	{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E}.Release|Any CPU.Build.0 = Release|Any CPU
+								{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+								{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+								{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{AA2AD188-B903-46DF-AE43-4769DBF788E9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{AA2AD188-B903-46DF-AE43-4769DBF788E9}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{AA2AD188-B903-46DF-AE43-4769DBF788E9}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{AA2AD188-B903-46DF-AE43-4769DBF788E9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6A71CD77-320C-458F-97B3-BA8F4CB530C6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6A71CD77-320C-458F-97B3-BA8F4CB530C6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6A71CD77-320C-458F-97B3-BA8F4CB530C6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6A71CD77-320C-458F-97B3-BA8F4CB530C6}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
-	    {E007586F-9760-4744-BB25-EDEFD6BA860C} = {D3FCB669-E93F-4F0B-B9C5-6592CE93AC7F}
+					{E007586F-9760-4744-BB25-EDEFD6BA860C} = {D3FCB669-E93F-4F0B-B9C5-6592CE93AC7F}
 		{A4F6ADD5-85FD-4F67-8B29-549DDDF6F82E} = {D3FCB669-E93F-4F0B-B9C5-6592CE93AC7F}
+		{47EB60F8-9C89-4D13-8243-B77B01A4BA53} = {318796AF-A927-4A13-BAEE-FD13551DE91A}
+		{AA2AD188-B903-46DF-AE43-4769DBF788E9} = {47EB60F8-9C89-4D13-8243-B77B01A4BA53}
+		{6A71CD77-320C-458F-97B3-BA8F4CB530C6} = {47EB60F8-9C89-4D13-8243-B77B01A4BA53}
 	EndGlobalSection
 EndGlobal