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/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
+```