diff --git a/src/task_1/index.ts b/src/task_1/index.ts
index 53a04d7..a8f8b78 100644
--- a/src/task_1/index.ts
+++ b/src/task_1/index.ts
@@ -26,3 +26,29 @@ class Calculator {
         return (this.a + this.b).toString();
     }
 }
+
+class Decor extends Calculator
+{
+    protected calculators: Calculator;
+    constructor(a: number, b: number)
+    {
+        super(a, b)
+        this.calculators = new Calculator(a, b)
+    }
+}
+
+class DecorateRu extends Decor
+{
+    public exec(): string
+    {
+        return 'Результат сложения ${this.a} + ${this.b} = ${this.calculators.exec()}'
+    }
+}
+
+class DecorateEn extends Decor
+{
+    public exec(): string
+    {
+        return 'Result of the addition operation ${this.a} + ${this.b} = ${this.calculators.exec()}'
+    }
+}
\ No newline at end of file
diff --git a/src/task_2/index.ts b/src/task_2/index.ts
index 06535aa..010a14a 100644
--- a/src/task_2/index.ts
+++ b/src/task_2/index.ts
@@ -5,10 +5,28 @@
  * Когда присваивается некорректный e-mail возбуждается ошибка.
 */
 
-class Example {
-    public email: string = "";
+function check_mail(target: Object, propertyKey: string): any{
+    let email = "";
+    let discriptor: PropertyDescriptor = {
+        get: function()
+        {
+            return email;
+        },
+        set: function(newmail: string)
+        {
+            let mail_write = /[a-zA-Z0-9]+@[a-zA-Z0-9]+.[a-zA-Z0-9]+/
+            if (mail_write.test(newmail))
+            {
+                email = newmail; 
+                console.log('email valid')  
+                
+            }
+            else
+            {
+                throw "Invalid email"  
+            }       
+        }
+    }
+    return discriptor;
 }
 
-let exampleInstance = new Example();
-exampleInstance.email = "fkkldfjg"; // генерирует эксепшен
-exampleInstance.email = "misha@mail.ru"; // выводит в консоль e-mail valid
diff --git a/src/task_4/index.ts b/src/task_4/index.ts
index dc0e179..b8c02cc 100644
--- a/src/task_4/index.ts
+++ b/src/task_4/index.ts
@@ -6,6 +6,6 @@ function getProperty<T, K extends keyof T>(obj: T, key: K): T[K] {
     return obj[key];
 }
 
-const x = undefined;
+const x = {m: 7};
 
-console.log(getProperty(x, "m")); 
\ No newline at end of file
+console.log(getProperty(x, "m"));