diff --git a/RohamHayedi/RohamHayedi.txt b/RohamHayedi/RohamHayedi.txt
new file mode 100644
index 0000000..842491b
--- /dev/null
+++ b/RohamHayedi/RohamHayedi.txt
@@ -0,0 +1,2 @@
+Full Name: Roham Hayedi
+Student Number: 9831107
\ No newline at end of file
diff --git a/RohamHayedi/lab4/Person.java b/RohamHayedi/lab4/Person.java
new file mode 100644
index 0000000..c570818
--- /dev/null
+++ b/RohamHayedi/lab4/Person.java
@@ -0,0 +1,25 @@
+public class Person {
+
+    private final String firstName;
+    private final String lastName;
+
+    public Person(String firstName, String lastName){
+
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    @Override
+    public String toString() {
+        return firstName +" "+
+                lastName ;
+    }
+}
diff --git a/RohamHayedi/lab4/Run.java b/RohamHayedi/lab4/Run.java
new file mode 100644
index 0000000..313c81a
--- /dev/null
+++ b/RohamHayedi/lab4/Run.java
@@ -0,0 +1,66 @@
+import ir.huri.jcal.JalaliCalendar;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+
+public class Run {
+    public static void main(String[] args) {
+
+        VotingSystem votingSystem = new VotingSystem();
+        ArrayList<String> options0 = new ArrayList<>();
+        ArrayList<String> options1 = new ArrayList<>();
+        ArrayList<String> options2 = new ArrayList<>();
+
+        options0.add("Pizza");
+        options0.add("Sandwich");
+        options0.add("Neither");
+
+        options1.add("Saturday");
+        options1.add("Sunday");
+        options1.add("Monday");
+
+        votingSystem.createVoting("Pizza or Sandwich?", 0, options0);
+        votingSystem.createVoting("When are you available?", 1, options1);
+
+        Person me = new Person("Roham", "Hayedi");
+        ArrayList<String> myChoices0 = new ArrayList<>();
+        ArrayList<String> myChoices1 = new ArrayList<>();
+        myChoices0.add("Pizza");
+        myChoices1.add("Saturday");
+        myChoices1.add("Saturday");
+        myChoices1.add("Sunday");
+
+        votingSystem.vote(0, me, myChoices0);
+        votingSystem.vote(1, me, myChoices1);
+        System.out.println("Print questions:");
+        votingSystem.printVotingQuestions();
+        System.out.println("\nPrint voting 0 :");
+        votingSystem.printVoting(0);
+        System.out.println("\nPrint result 0 :");
+        votingSystem.printResult(0);
+        System.out.println("\nPrint voting 1 :");
+        votingSystem.printVoting(1);
+        System.out.println("\nPrint result 1 :");
+        votingSystem.printResult(1);
+
+        Person person = new Person("kc", "sd");
+        ArrayList<String> kcsdChoices0 = new ArrayList<String>();
+        ArrayList<String> kcsdChoices1 = new ArrayList<String>();
+        kcsdChoices0.add("Neither");
+        kcsdChoices1.add("Saturday");
+        votingSystem.vote(1, person, kcsdChoices1);
+        votingSystem.vote(0, person, kcsdChoices0);
+        votingSystem.vote(0, person, kcsdChoices0);
+
+        System.out.println("\nPrint voting 0 :");
+        votingSystem.printVoting(0);
+        System.out.println("\nPrint result 0 :");
+        votingSystem.printResult(0);
+        System.out.println("\nPrint voting 1 :");
+        votingSystem.printVoting(1);
+        System.out.println("\nPrint result 1 :");
+        votingSystem.printResult(1);
+
+    }
+}
diff --git a/RohamHayedi/lab4/Vote.java b/RohamHayedi/lab4/Vote.java
new file mode 100644
index 0000000..8e01ea3
--- /dev/null
+++ b/RohamHayedi/lab4/Vote.java
@@ -0,0 +1,36 @@
+import ir.huri.jcal.JalaliCalendar;
+
+import java.util.Objects;
+
+public class Vote {
+
+    private final Person person;
+    private final String date;
+
+    public Vote(Person person, String date){
+        this.person = person;
+        this.date = date;
+    }
+
+    public Person getPerson() {
+        return person;
+    }
+
+    public String getDate() {
+        return date;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Vote)) return false;
+        Vote vote = (Vote) o;
+        return Objects.equals(person, vote.person) &&
+                Objects.equals(date, vote.date);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(person, date);
+    }
+}
diff --git a/RohamHayedi/lab4/Voting.java b/RohamHayedi/lab4/Voting.java
new file mode 100644
index 0000000..4ae8916
--- /dev/null
+++ b/RohamHayedi/lab4/Voting.java
@@ -0,0 +1,79 @@
+import ir.huri.jcal.JalaliCalendar;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class Voting {
+
+    private final int type;
+    private final String question;
+    private ArrayList<Person> voters;
+    private HashMap<String, HashSet<Vote>> polls;
+
+    public Voting(String question, int type,  ArrayList<String> choices){
+        this.type = type;
+        this.question = question;
+        polls = new HashMap<>();
+        voters = new ArrayList<>();
+        for (String choice : choices){
+            polls.put(choice, new HashSet<>());
+        }
+    }
+
+    public void creatChoice(String choice){
+        polls.put(choice, new HashSet<>());
+    }
+
+    public void vote(Person person, ArrayList<String> choices){
+        if (type == 0 && choices.size() > 1) {
+            System.out.println(person + "-> This voting (" + question + ") accepts only single choices");
+        }
+        else {
+            if (!voters.contains(person)) {
+                voters.add(person);
+                Vote vote = new Vote(person, new JalaliCalendar().toString());
+                for (String choice : choices)
+                    if (polls.containsKey(choice))
+                        polls.get(choice).add(vote);
+                    else {
+                        System.out.println(person + "->The input (" + choice + ") is not among the choices");
+                    }
+            }else{
+                System.out.println("The same person cannot vote twice");
+            }
+        }
+    }
+
+    public String getQuestion() {
+        return question;
+    }
+
+    public void printVoters() {
+        int i = 0;
+        for (Person person : voters) {
+            System.out.println(i + "-" + person);
+        }
+    }
+
+    public HashMap<String, HashSet<Vote>> getPolls() {
+        return polls;
+    }
+
+    public void printChoices(){
+        AtomicInteger i = new AtomicInteger(1);
+        polls.forEach((k,v) -> System.out.println(i.getAndIncrement() + "- " + k));
+    }
+
+    public void printResult(){
+        System.out.println(question);
+        for (Map.Entry<String, HashSet<Vote>> entry : polls.entrySet()) {
+            String choice = entry.getKey();
+            HashSet<Vote> votes = entry.getValue();
+            System.out.println(choice + " -> " + votes.size());
+            votes.forEach(vote -> System.out.println(vote.getPerson() + " " + vote.getDate()));
+        }
+    }
+}
diff --git a/RohamHayedi/lab4/VotingSystem.java b/RohamHayedi/lab4/VotingSystem.java
new file mode 100644
index 0000000..067d269
--- /dev/null
+++ b/RohamHayedi/lab4/VotingSystem.java
@@ -0,0 +1,45 @@
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
+
+public class VotingSystem {
+
+    private ArrayList<Voting> votingList;
+
+    public VotingSystem(){
+        votingList = new ArrayList<>();
+    }
+
+    public void createVoting(String question, int type, ArrayList<String> choices ){
+        votingList.add(new Voting(question, type, choices));
+    }
+
+    public void deleteVoting(int index){
+        votingList.remove(index);
+    }
+
+    public void vote(int index, Person person, ArrayList<String> votes){
+        votingList.get(index).vote(person, votes);
+    }
+
+    public void printVotingQuestions() {
+        for (Voting voting : votingList){
+            System.out.println(voting.getQuestion());
+        }
+    }
+
+    public void printVoting(int index){
+        if (index < votingList.size()) {
+            System.out.println(votingList.get(index).getQuestion());
+            votingList.get(index).printChoices();
+        }else
+            System.out.println("Wrong index");
+    }
+
+    public void printResult(int index) {
+        if (index < votingList.size()) {
+            votingList.get(index).printResult();
+        }else
+            System.out.println("Wrong index");
+    }
+}
diff --git a/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Circle.java b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Circle.java
new file mode 100644
index 0000000..42b6ccb
--- /dev/null
+++ b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Circle.java
@@ -0,0 +1,32 @@
+public class Circle extends Shape {
+
+    private double radius;
+
+    public Circle(double radius){
+        this.radius = radius;
+    }
+
+    public double getRadius() {
+        return radius;
+    }
+
+    @Override
+    public void draw() {
+        System.out.println((char) 0x25EF);
+    }
+
+    @Override
+    public double calculateParameter() {
+        return 2 * 3.14 * radius;
+    }
+
+    @Override
+    public double calculateArea() {
+        return 3.14 * radius*radius;
+    }
+
+    @Override
+    public String toString() {
+        return "radius = " + radius;
+    }
+}
diff --git a/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Paint.java b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Paint.java
new file mode 100644
index 0000000..ed2d6eb
--- /dev/null
+++ b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Paint.java
@@ -0,0 +1,40 @@
+import java.util.ArrayList;
+import java.util.logging.SocketHandler;
+
+public class Paint {
+
+    private ArrayList<Shape> shapes;
+
+    public Paint(){
+        shapes = new ArrayList<>();
+    }
+
+    public void addShape(Shape shape){
+        shapes.add(shape);
+    }
+
+    public void drawAll(){
+        for(Shape shape : shapes){
+            shape.draw();
+        }
+    }
+
+    public void describeEqualSides(){
+        System.out.println("describeEqualSides::");
+        for (Shape shape : shapes){
+            if (shape instanceof Triangle) {
+                if (((Triangle) shape).isEquilateral())
+                    System.out.println(shape);
+            }else if (shape instanceof Rectangle)
+                if (((Rectangle) shape).isSquare())
+                    System.out.println(shape);
+        }
+    }
+
+    public void printAll(){
+        for (Shape shape : shapes){
+            System.out.println(shape);
+        }
+    }
+
+}
diff --git a/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Polygon.java b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Polygon.java
new file mode 100644
index 0000000..545d4d1
--- /dev/null
+++ b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Polygon.java
@@ -0,0 +1,20 @@
+import java.util.ArrayList;
+
+public abstract class Polygon extends Shape {
+
+    private ArrayList<Double> sides;
+
+    public Polygon(double... args){
+        sides = new ArrayList<>();
+        for (double side : args){
+            sides.add(side);
+        }
+    }
+
+    @Override
+    public abstract void draw();
+
+    public ArrayList<Double> getSides() {
+        return sides;
+    }
+}
diff --git a/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Rectangle.java b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Rectangle.java
new file mode 100644
index 0000000..3f43db9
--- /dev/null
+++ b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Rectangle.java
@@ -0,0 +1,50 @@
+import java.util.ArrayList;
+
+public class Rectangle extends Polygon {
+
+    public Rectangle(double... args){
+        super(args);
+    }
+
+    @Override
+    public void draw() {
+        System.out.println((char) 0x25AD);
+    }
+
+    @Override
+    public double calculateArea() {
+        ArrayList<Double> sides = super.getSides();
+        return sides.get(0).equals(sides.get(1)) ? sides.get(0) * sides.get(2) : sides.get(0) * sides.get(1);
+    }
+
+    @Override
+    public double calculateParameter() {
+        double param = 0;
+        for (double side : super.getSides()){
+            param += side;
+        }
+        return param;
+    }
+
+    public boolean isSquare(){
+        ArrayList<Double> sides = super.getSides();
+        double sampleSide = sides.get(0);
+        for (double side : sides){
+            if (side != sampleSide)
+                return false;
+        }
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder stringBuilder = new StringBuilder();
+        ArrayList<Double> sides = super.getSides();
+        stringBuilder.append("First pair: ");
+        stringBuilder.append(sides.get(0));
+        stringBuilder.append(", Second pair: ");
+        stringBuilder.append(!sides.get(0).equals(sides.get(1)) ? sides.get(1) : sides.get(2));
+
+        return super.toString() + stringBuilder;
+    }
+}
diff --git a/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Shape.java b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Shape.java
new file mode 100644
index 0000000..127a797
--- /dev/null
+++ b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Shape.java
@@ -0,0 +1,28 @@
+public class Shape extends Paint {
+
+    public double calculateParameter() {
+        return 0;
+    }
+
+    public double calculateArea() {
+        return 0;
+    }
+
+    public void draw(){}
+
+    @Override
+    public boolean equals(Object obj) {
+        return super.equals(obj);
+    }
+
+    @Override
+    public String toString() {
+        if (this instanceof Triangle)
+            return "Triangle:: ";
+        else if (this instanceof Rectangle)
+            return "Rectangle:: ";
+        else if (this instanceof Circle)
+            return "Circle:: ";
+        return super.toString();
+    }
+}
diff --git a/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Triangle.java b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Triangle.java
new file mode 100644
index 0000000..8b3cc85
--- /dev/null
+++ b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/Triangle.java
@@ -0,0 +1,31 @@
+import java.util.ArrayList;
+
+public class Triangle extends Polygon {
+
+    public Triangle(double... args){
+        super(args);
+    }
+
+    @Override
+    public void draw() {
+        System.out.println((char) 0x25B3);
+    }
+
+    public boolean isEquilateral(){
+        return super.getSides().get(0).equals(super.getSides().get(1)) &&
+                super.getSides().get(0).equals(super.getSides().get(2));
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder stringBuilder = new StringBuilder();
+        ArrayList<Double> sides = super.getSides();
+        stringBuilder.append("side1: ");
+        stringBuilder.append(sides.get(0));
+        stringBuilder.append(", side2: ");
+        stringBuilder.append(sides.get(1));
+        stringBuilder.append(", side3: ");
+        stringBuilder.append(sides.get(2));
+        return super.toString() + stringBuilder.toString();
+    }
+}
diff --git a/RohamHayedi/lab5/Part1-PaintWithPolymorphism/main.java b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/main.java
new file mode 100644
index 0000000..b8a92f9
--- /dev/null
+++ b/RohamHayedi/lab5/Part1-PaintWithPolymorphism/main.java
@@ -0,0 +1,31 @@
+public class main {
+
+    public static void main(String[] args) {
+        Paint paint = new Paint();
+
+        Triangle triangle1 = new Triangle(1,2,3);
+        Triangle triangle2 = new Triangle(2,2,2);
+        Triangle triangle3 = new Triangle(3,4,5);
+
+        Rectangle rectangle1 = new Rectangle(1,2,1,2);
+        Rectangle rectangle2 = new Rectangle(2,2,2,2);
+        Rectangle rectangle3 = new Rectangle(3,2,3,2);
+
+        Circle circle1 = new Circle(2);
+        Circle circle2 = new Circle(3);
+        Circle circle3 = new Circle(5);
+
+        paint.addShape(triangle1);
+        paint.addShape(triangle2);
+        paint.addShape(triangle3);
+        paint.addShape(rectangle1);
+        paint.addShape(rectangle2);
+        paint.addShape(rectangle3);
+        paint.addShape(circle1);
+        paint.addShape(circle2);
+        paint.addShape(circle3);
+
+        paint.drawAll();
+        paint.printAll();
+    }
+}
diff --git a/RohamHayedi/lab5/Part2-Correction.txt b/RohamHayedi/lab5/Part2-Correction.txt
new file mode 100644
index 0000000..6a7393d
--- /dev/null
+++ b/RohamHayedi/lab5/Part2-Correction.txt
@@ -0,0 +1,19 @@
+public static void main(String[] args) {
+        Circle circle1 = new Shape(19);
+        Shape circle2 = new Circle(3);
+        Triangle rect1 = new Triangle(1,4,1);
+        Polygon rect2 = new Rectangle(8,5,8,5);
+        Rectangle rec3 = new Shape(6,6,6,6);
+        Polygon tri1 = new Triangle(2,2,2);
+        Triangle tri2 = new Triangle(4,4,6);
+        Shape tri3 = new Triangle(2,2,2);
+
+        circle1 = (Circle) circle2;
+        rect2 = rec3;
+        tri1 = (Polygon) tri3;
+        circle2 = tri3;
+        tri3 = tri2;
+
+        rec3 = new Shape(2,3,2);
+        System.out.println(rec3);
+    }
\ No newline at end of file