diff --git a/CourseApp.Tests/DocumentTest.cs b/CourseApp.Tests/DocumentTest.cs
new file mode 100644
index 0000000..41eb790
--- /dev/null
+++ b/CourseApp.Tests/DocumentTest.cs
@@ -0,0 +1,130 @@
+namespace CourseApp.Tests
+{
+    using Xunit;
+
+    public class DocumentTest
+    {
+        [Fact]
+        public void OfficialTest()
+        {
+            var officDoc = new Official("Official memo �12", "Official memo", 451);
+            Assert.Equal("Official memo �12", officDoc.Name);
+            Assert.Equal("Official memo", officDoc.Type);
+            Assert.Equal(451, officDoc.Size);
+        }
+
+        [Fact]
+        public void ProtocolTest()
+        {
+            var protDoc = new Protocol("Protocol �22122", "Protocol", 366);
+            Assert.Equal("Protocol �22122", protDoc.Name);
+            Assert.Equal("Protocol", protDoc.Type);
+            Assert.Equal(366, protDoc.Size);
+        }
+
+        [Fact]
+        public void AnalyticalTest()
+        {
+            var anDoc = new Analytical("Special conclusion", "�onclusion", 215);
+            Assert.Equal("Special conclusion", anDoc.Name);
+            Assert.Equal("�onclusion", anDoc.Type);
+            Assert.Equal(215, anDoc.Size);
+        }
+
+        [Fact]
+        public void OfficialDocumentSizeTest()
+        {
+            var officDoc = new Official("Official memo �12", "Official memo", 451);
+            var result = officDoc.DocumentSize();
+            Assert.Equal("451 �� ", result);
+        }
+
+        [Fact]
+        public void ProtocolDocumentSizeTest()
+        {
+            var protDoc = new Protocol("Protocol �22122", "Protocol", 366);
+            var result = protDoc.DocumentSize();
+            Assert.Equal("366 �� ", result);
+        }
+
+        [Fact]
+        public void AnalyticalDocumentSizeTest()
+        {
+            var anDoc = new Analytical("Special conclusion", "�onclusion", 215);
+            var result = anDoc.DocumentSize();
+            Assert.Equal("215 �� ", result);
+        }
+
+        [Fact]
+        public void OfficialWayTest()
+        {
+            var officDoc = new Official("Official memo �12", "Official memo", 451);
+            var result = officDoc.Way();
+            Assert.Equal("C:/files", result);
+        }
+
+        [Fact]
+        public void ProtocolWayTest()
+        {
+            var protDoc = new Protocol("Protocol �22122", "Protocol", 366);
+            var result = protDoc.Way();
+            Assert.Equal("D:/files/documents", result);
+        }
+
+        [Fact]
+        public void AnalyticalWayTest()
+        {
+            var anDoc = new Analytical("Special conclusion", "�onclusion", 215);
+            var result = anDoc.Way();
+            Assert.Equal("C:/work/documents", result);
+        }
+
+        [Fact]
+        public void OfficialNameOfElTest()
+        {
+            var officDoc = new Official("Official memo �12", "Official memo", 451);
+            var result = officDoc.NameOfEl();
+            Assert.Equal("OfficialDocument: ", result);
+        }
+
+        [Fact]
+        public void ProtocolNameOfElTest()
+        {
+            var protDoc = new Protocol("Protocol �22122", "Protocol", 366);
+            var result = protDoc.NameOfEl();
+            Assert.Equal("ProtocolDocument: ", result);
+        }
+
+        [Fact]
+        public void AnalyticalNameOfElTest()
+        {
+            var anDoc = new Analytical("Special conclusion", "�onclusion", 215);
+            var result = anDoc.NameOfEl();
+            Assert.Equal("AnalyticalDocument: ", result);
+        }
+
+        [Fact]
+        public void OfficialToStringTest()
+        {
+            var officDoc = new Official("Official memo �12", "Official memo", 451);
+            var result = officDoc.ToString();
+            Assert.Equal("Official memo �12; 451 ��; Official memo", result);
+        }
+
+        [Fact]
+        public void ProtocolToStringTest()
+        {
+            var protDoc = new Protocol("Protocol �22122", "Protocol", 366);
+            var result = protDoc.ToString();
+            Assert.Equal("Protocol �22122; 366 ��; Protocol", result);
+        }
+
+        [Fact]
+        public void AnalyticalToStringTest()
+        {
+            var anDoc = new Analytical("Special conclusion", "�onclusion", 215);
+            var result = anDoc.ToString();
+            Assert.Equal("Special conclusion; 215 ��; �onclusion", result);
+        }
+    }
+}
\ No newline at end of file
diff --git a/CourseApp/Analytical.cs b/CourseApp/Analytical.cs
new file mode 100644
index 0000000..95b4784
--- /dev/null
+++ b/CourseApp/Analytical.cs
@@ -0,0 +1,31 @@
+namespace CourseApp;
+
+using System;
+
+public class Analytical : Document
+{
+    public Analytical(string name, string type, double size)
+        : base(name, type, size)
+    {
+    }
+
+    public override string DocumentSize()
+    {
+        return $"{Size} Мб ";
+    }
+
+    public override string Way()
+    {
+        return "C:/work/documents";
+    }
+
+    public override string NameOfEl()
+    {
+        return "AnalyticalDocument: ";
+    }
+
+    public override string ToString()
+    {
+        return $"{Name}; {Size} Мб; {Type}";
+    }
+}
\ No newline at end of file
diff --git a/CourseApp/Document.cs b/CourseApp/Document.cs
new file mode 100644
index 0000000..326893e
--- /dev/null
+++ b/CourseApp/Document.cs
@@ -0,0 +1,39 @@
+namespace CourseApp;
+
+using System;
+
+public abstract class Document
+{
+    public Document(string name, string type, double size)
+    {
+        this.Name = name;
+        this.Type = type;
+        this.Size = size;
+    }
+
+    public string Name { get; set; }
+
+    public string Type { get; set; }
+
+    public double Size { get; set; }
+
+    public void Print()
+    {
+        Console.Write($"Название документа: {Name}  Тип документа: {Type}  Размер документа: {Size} Мб");
+    }
+
+    public virtual string DocumentSize()
+    {
+        return "200 Мб";
+    }
+
+    public virtual string Way()
+    {
+        return "sss";
+    }
+
+    public virtual string NameOfEl()
+    {
+        return "3";
+    }
+}
\ No newline at end of file
diff --git a/CourseApp/Phone.cs b/CourseApp/Phone.cs
new file mode 100644
index 0000000..1c8e407
--- /dev/null
+++ b/CourseApp/Phone.cs
@@ -0,0 +1,38 @@
+namespace CourseApp
+{
+    using System;
+
+    public class Phone
+    {
+        private float diaonal;
+
+        public Phone(string name, float diagonal)
+        {
+            Name = name;
+            Diagonal = diagonal;
+        }
+
+        public string Name { get; set; }
+
+        public float Diagonal
+        {
+            get
+            {
+                return diaonal;
+            }
+
+            set
+            {
+                if (value > 0 && value < 20)
+                {
+                    this.diaonal = value;
+                }
+            }
+        }
+
+        public void Show()
+        {
+            Console.WriteLine($"{Name} with diagonal {diaonal}");
+        }
+    }
+}
\ No newline at end of file
diff --git a/CourseApp/Program.cs b/CourseApp/Program.cs
index d6d2c87..030f047 100644
--- a/CourseApp/Program.cs
+++ b/CourseApp/Program.cs
@@ -6,6 +6,20 @@ public class Program
     {
         public static void Main(string[] args)
         {
+            Phone phone1 = new Phone("iPhone", -7);
+            phone1.Show();
+            phone1.Diagonal = 7;
+            phone1.Show();
+            phone1.Diagonal = -16;
+            phone1.Show();
+
+            Phone tablet = new Phone("Android", 6);
+            tablet.Diagonal = 6;
+            tablet.Show();
+            tablet.Diagonal = -10;
+            tablet.Show();
+            tablet.Diagonal = 8;
+            tablet.Show();
             Console.WriteLine("Hello World");
         }
     }
diff --git a/CourseApp/Protocol.cs b/CourseApp/Protocol.cs
new file mode 100644
index 0000000..f0fd3ea
--- /dev/null
+++ b/CourseApp/Protocol.cs
@@ -0,0 +1,31 @@
+namespace CourseApp;
+
+using System;
+
+public class Protocol : Document
+{
+    public Protocol(string name, string type, double size)
+        : base(name, type, size)
+    {
+    }
+
+    public override string DocumentSize()
+    {
+        return $"{Size} Мб ";
+    }
+
+    public override string Way()
+    {
+        return "D:/files/documents";
+    }
+
+    public override string NameOfEl()
+    {
+        return "ProtocolDocument: ";
+    }
+
+    public override string ToString()
+    {
+        return $"{Name}; {Size} Мб; {Type}";
+    }
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index a79bfa3..2611643 100644
--- a/README.md
+++ b/README.md
@@ -33,4 +33,4 @@ Finally you may work with migration (from `WebApplication` folder). The followin
 
 ```
 dotnet ef migrations add InitialMigration
-```
\ No newline at end of file
+```