diff --git a/lesson_3/exercise_2.cpp b/lesson_3/exercise_2.cpp
index 4058438..1962836 100644
--- a/lesson_3/exercise_2.cpp
+++ b/lesson_3/exercise_2.cpp
@@ -19,21 +19,48 @@ Matrix::Matrix(const int size) : matrixSize(size), matrixCapacity(size * size)
 }
 
 /*
- * Перегрузка операторов [][]
+ * Перегрузка операторов итератора
  */
-Matrix::Iterator::Iterator(double *row) : currentRow(row)
+Matrix::Iterator::Iterator(double *pointer) : current(pointer)
 {
 }
 
 double& Matrix::Iterator::operator[](size_t i)
 {
-    return *(currentRow + i);
+    return *(current + i);
+}
+
+Matrix::Iterator& Matrix::Iterator::operator ++()
+{
+    ++current;
+    return *this;
+}
+
+bool Matrix::Iterator::operator !=(const Iterator &iterator)
+{
+    return current != iterator.current;
+}
+
+double& Matrix::Iterator::operator *()
+{
+    return *current;
 }
 
 Matrix::Iterator Matrix::operator[](size_t i)
 {
     return Iterator(array + i * matrixSize);
 }
+
+Matrix::Iterator Matrix::begin()
+{
+    return Iterator(array);
+}
+
+Matrix::Iterator Matrix::end()
+{
+    return Iterator(array + matrixCapacity);
+}
+
 /*
  * Расчет определителя
  */
diff --git a/lesson_3/exercise_2.hpp b/lesson_3/exercise_2.hpp
index 62a4cc9..b7c2560 100644
--- a/lesson_3/exercise_2.hpp
+++ b/lesson_3/exercise_2.hpp
@@ -33,13 +33,18 @@ public:
     class Iterator
     {
     private:
-        double *currentRow;
+        double *current;
     public:
-        Iterator(double *row);
+        Iterator(double *pointer);
         double& operator[](size_t i);
+        Iterator& operator ++();
+        bool operator !=(const Iterator &iterator);
+        double& operator *();
     };
 
     Iterator operator[](size_t i);
+    Iterator begin();
+    Iterator end();
 
     ~Matrix();
 };
diff --git a/lesson_3/exercise_3.cpp b/lesson_3/exercise_3.cpp
new file mode 100644
index 0000000..cd7c169
--- /dev/null
+++ b/lesson_3/exercise_3.cpp
@@ -0,0 +1,26 @@
+/*
+ * exercise_3.cpp
+ *
+ *  Created on: 30 сент. 2021 г.
+ *      Author: alexander
+ */
+
+#include <iostream>
+#include <iomanip>
+#include "exercise_3.hpp"
+#include "exercise_2.hpp"
+
+using namespace std;
+
+void exercise_3()
+{
+    Matrix m(4);
+    m.fillRandom();
+
+    for (const double &i : m)
+    {
+        cout << setw(5) << i;
+    }
+
+    cout << endl;
+}
diff --git a/lesson_3/exercise_3.hpp b/lesson_3/exercise_3.hpp
new file mode 100644
index 0000000..b0b26bb
--- /dev/null
+++ b/lesson_3/exercise_3.hpp
@@ -0,0 +1,10 @@
+/*
+ * exercise_3.hpp
+ *
+ *  Created on: 30 сент. 2021 г.
+ *      Author: alexander
+ */
+
+#pragma once
+
+void exercise_3();
diff --git a/lesson_3/main.cpp b/lesson_3/main.cpp
index c60dec9..c792793 100644
--- a/lesson_3/main.cpp
+++ b/lesson_3/main.cpp
@@ -7,11 +7,13 @@
 
 #include "exercise_1.hpp"
 #include "exercise_2.hpp"
+#include "exercise_3.hpp"
 
 int main()
 {
-//    exercise_1();
+    exercise_1();
     exercise_2();
+    exercise_3();
 
     return 0;
 }