diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..92409ee
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/.idea/
+README.md
+pointer-nested-classes.iml
diff --git a/com/src/Collection.java b/com/src/Collection.java
new file mode 100644
index 0000000..1f70ce0
--- /dev/null
+++ b/com/src/Collection.java
@@ -0,0 +1,73 @@
+package src;
+
+public class Collection {
+
+    private Integer[] integers;
+
+    public Collection(Integer[] integers) {
+        this.integers = integers;
+    }
+
+    public Integer[] getIntegers() {
+        return integers;
+    }
+
+    public void setIntegers(Integer[] integers) {
+        this.integers = integers;
+    }
+
+    public static class FirstIteratorImplementator implements Iterator {
+        private Integer[] integers;
+
+        public FirstIteratorImplementator(Integer[] integers) {
+            this.integers = integers;
+        }
+
+        public Integer[] getIntegers() {
+            return integers;
+        }
+
+
+        @Override
+        public boolean hasNext() {
+            for (int i = 0; i < integers.length; i++) {
+                System.out.println(integers[i]);
+            }
+            return false;
+        }
+
+
+        @Override
+        public Object next() {
+            for (int i = 0; i < integers.length; i++) {
+                if (i % 2 != 0) {
+                    integers[i] = null;
+                }
+                System.out.println(integers[i]);
+            }
+            return integers;
+        }
+    }
+
+    public static class secondIteratorImplementator implements Iterator {
+        private Integer[] integers;
+
+        public secondIteratorImplementator(Integer[] integers) {
+            this.integers = integers;
+        }
+
+
+        @Override
+        public boolean hasNext() {
+            return false;
+        }
+
+        @Override
+        public Object next() {
+            for (int i = 0; i < integers.length; i += 2) {
+                System.out.println(integers[i]);
+            }
+            return integers;
+        }
+    }
+}
diff --git a/com/src/Iterator.java b/com/src/Iterator.java
new file mode 100644
index 0000000..34a6460
--- /dev/null
+++ b/com/src/Iterator.java
@@ -0,0 +1,7 @@
+package src;
+
+public interface Iterator {
+    boolean hasNext();
+
+    Object next();
+}
diff --git a/com/src/IteratorForEveryFifthElement.java b/com/src/IteratorForEveryFifthElement.java
new file mode 100644
index 0000000..9759bcd
--- /dev/null
+++ b/com/src/IteratorForEveryFifthElement.java
@@ -0,0 +1,38 @@
+package src;
+
+public class IteratorForEveryFifthElement {
+    private Integer[] integers;
+
+    public IteratorForEveryFifthElement(Integer[] integers) {
+        this.integers = integers;
+    }
+
+    public Integer[] getIntegers() {
+        return integers;
+    }
+
+    public void setIntegers(Integer[] integers) {
+        this.integers = integers;
+    }
+
+    public void iterateEveryFifthElemant(Integer[] inputtedIntegers) {
+        for (int i = 0; i < inputtedIntegers.length; i += 5) {
+            if (inputtedIntegers[i] % 2 == 0) {
+                inputtedIntegers[i] -= 100;
+                System.out.println(inputtedIntegers[i]);
+            }
+        }
+    }
+
+    public static class InsideIterator {
+        public static void changeNumberIfItOdd(Integer[] inputtedIntegers) {
+            for (int i = 0; i < inputtedIntegers.length; i += 2) {
+                if (inputtedIntegers[i] % 2 == 0) {
+                    inputtedIntegers[i] += 1;
+                    System.out.println(inputtedIntegers[i]);
+                }
+            }
+
+        }
+    }
+}
diff --git a/com/src/Main.java b/com/src/Main.java
new file mode 100644
index 0000000..42bbe68
--- /dev/null
+++ b/com/src/Main.java
@@ -0,0 +1,48 @@
+package src;
+
+public class Main {
+
+    public static void main(String[] args) {
+
+        Collection FirstCollection = new Collection(new Integer[]{10, 11, 12, 13, 14, 15, 5, 4, 54, 185, 945, 645, 64, 6, 84, 68, 4, 684, 68, 4, 48, 684, 7165});
+        Collection secondCollection = new Collection(new Integer[]{10, 11, 12, 13, 14, 15, 5, 4, 54, 185, 945, 645, 64, 6, 84, 68, 4, 684, 68, 4, 48, 684, 7165});
+        Collection thirdCollection = new Collection(new Integer[]{10, 11, 12, 13, 14, 15, 5, 4, 54, 185, 945, 645, 64, 6, 84, 68, 4, 684, 68, 4, 48, 684, 7165});
+        Collection fourthCollection = new Collection(new Integer[]{10, 11, 12, 13, 14, 15, 5, 4, 54, 185, 945, 645, 64, 6, 84, 68, 4, 684, 68, 4, 48, 684, 7165});
+        Collection fifthCollection = new Collection(new Integer[]{10, 11, 12, 13, 14, 15, 5, 4, 54, 185, 945, 645, 64, 6, 84, 68, 4, 684, 68, 4, 48, 684, 7165});
+        Iterator iterator = new Collection.FirstIteratorImplementator(thirdCollection.getIntegers()) {
+            public boolean hasNext() {
+                return false;
+            }
+
+            @Override
+            public Object next() {
+                printEveritThirdElementIfInEven(getIntegers());
+                return getIntegers();
+
+            }
+        };
+        System.out.println("First");
+        Collection.FirstIteratorImplementator FirstImplementator = new Collection.FirstIteratorImplementator(FirstCollection.getIntegers());
+        FirstImplementator.next();
+        FirstImplementator.hasNext();
+
+
+        System.out.println("\nSecond");
+        Collection.secondIteratorImplementator secondImplementator = new Collection.secondIteratorImplementator(secondCollection.getIntegers());
+        secondImplementator.next();
+
+        System.out.println("\n Third");
+        iterator.next();
+
+        System.out.println("\n Fourth");
+        IteratorForEveryFifthElement.InsideIterator.changeNumberIfItOdd(fifthCollection.getIntegers());
+    }
+
+    private static void printEveritThirdElementIfInEven(Integer[] ints) {
+        for (int i = 0; i < ints.length; i += 3) {
+            if (ints[i] % 2 != 0) {
+                System.out.println(ints[i]);
+            }
+        }
+    }
+}