diff --git a/CorsiInterface.php b/CorsiInterface.php
new file mode 100644
index 0000000..3941909
--- /dev/null
+++ b/CorsiInterface.php
@@ -0,0 +1,14 @@
+<?php
+/**
+ * Interfaccia per la gestione dei corsi
+ * @author Enrico Zimuel (enrico.zimuel@its-ictpiemonte.it)
+ */
+declare(strict_types=1);
+
+interface CorsiInterface
+{
+    public function getMediaCorsi(): float;
+    public function addCorso(string $corso): bool;
+    public function getCorsi(): array;
+    public function addVoto(string $corso, int $voto): bool;
+}
diff --git a/Esercizio.md b/Esercizio.md
new file mode 100644
index 0000000..674a067
--- /dev/null
+++ b/Esercizio.md
@@ -0,0 +1,4 @@
+## Esercizio
+
+Creare uno script PHP che selezioni a caso dei gruppi di studenti (minimo di 2 e massimo di 3 persone) da un elenco prestabilito.
+Lo script deve stampare il nome dei partecipanti di ogni gruppo separandoli con una virgola. Ogni gruppo deve essere stampato su una riga differente.
diff --git a/README.md b/README.md
index 11ac6e8..cca0444 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,9 @@
 ## Corso PHP Programming ITS - ICT Piemonte
 
-Esempio di file PHP utilizzati durante il corso di PHP Programming
-presso l'ITS ICT Piemonte.
+Esercizi sul PHP utilizzati durante il corso di *PHP Programming*
+presso l'[ITS ICT Piemonte](http://www.its-ictpiemonte.it/).
 
+### Object Oriented Programming
+
+- [Studente.php](https://github.com/ezimuel/Corso_PHP_ITS/blob/master/Studente.php)
+- [ShoppingCart.php](https://github.com/ezimuel/Corso_PHP_ITS/blob/master/ShoppingCart.php)
diff --git a/ShoppingCart.php b/ShoppingCart.php
new file mode 100644
index 0000000..9b9d119
--- /dev/null
+++ b/ShoppingCart.php
@@ -0,0 +1,26 @@
+<?php
+/**
+ * Classe per la gestione di un carrello elettronico
+ *
+ * @author Enrico Zimuel (enrico.zimuel@its-ictpiemonte.it)
+ */
+declare(strict_types=1);
+
+class ShoppingCart
+{
+    public function addProduct(string $product, int $quantity): bool
+    {
+    }
+
+	public function removeProduct(string $product): bool
+    {
+    }
+
+    public function changeQuantity(string $product, int $quantity): bool
+    {
+    }
+
+	public function removeAllProducts(): bool
+    {
+    }
+}
diff --git a/Studente.php b/Studente.php
index b228352..2437c37 100644
--- a/Studente.php
+++ b/Studente.php
@@ -1,8 +1,10 @@
-<?
+<?php
 /**
  * Classe di esempio
  * @author Enrico Zimuel (enrico.zimuel@its-ictpiemonte.it)
  */
+declare(strict_types=1);
+
 class Studente {
     public $nome;
     public $cognome;
@@ -32,17 +34,3 @@ public function getMediaEsami(): ?float
         return array_sum($this->corsi) / count($this->corsi);
     }
 }
-
-$studente = new Studente();
-$studente->nome = 'Mario';
-$studente->cognome = 'Rossi';
-$studente->email = 'mario.rossi@itspiemonte.it';
-$studente->dataDiNascita = '1/1/1995';
-
-$studente->addCorso('Cloud Services');
-$studente->addCorso('PHP Programming');
-
-$studente->addVotoEsame('Cloud Services', 24);
-$studente->addVotoEsame('PHP Programming', 26);
-
-printf("Media voto esami: %.2f\n", $studente->getMediaEsami());
diff --git a/StudenteInterface.php b/StudenteInterface.php
new file mode 100644
index 0000000..694a7af
--- /dev/null
+++ b/StudenteInterface.php
@@ -0,0 +1,18 @@
+<?php
+/**
+ * Interfaccia per la gestione degli studenti
+ * @author Enrico Zimuel (enrico.zimuel@its-ictpiemonte.it)
+ */
+declare(strict_types=1);
+
+interface StudenteInterface
+{
+    public function setNome(string $nome): bool;
+    public function getNome(): string;
+    public function setCognome(string $cognome): bool;
+    public function getCognome(): string;
+    public function setEmail(string $email): bool;
+    public function getEmail(): string;
+    public function setDataDiNascita(int $giorno, int $mese, int $anno): bool;
+    public function getDataDiNascita(): string; // nel formato "gg/mm/AAAA"
+}
diff --git a/drawer-groups/Classes/Drawer.php b/drawer-groups/Classes/Drawer.php
new file mode 100644
index 0000000..a989c20
--- /dev/null
+++ b/drawer-groups/Classes/Drawer.php
@@ -0,0 +1,31 @@
+
+<?php
+
+class Drawer
+{
+    protected $listToDraw = [];
+
+
+    public function __construct (array $listToDraw)
+    {
+        $this->listToDraw = $listToDraw;
+        shuffle($this->listToDraw);
+    }
+
+
+    public function makeGroups ($numberOfGroupMembers) : array
+    {
+        if(count($this->listToDraw) % $numberOfGroupMembers == 0)
+            return array_chunk($this->listToDraw, $numberOfGroupMembers);
+        
+        else
+        {
+            $list = array_chunk($this->listToDraw, $numberOfGroupMembers);
+            
+            for($i = 0; $i < count(end($list)); $i++)
+                array_push($list[$i], end($list)[$i]);
+
+            return $list;
+        }
+    }
+}
\ No newline at end of file
diff --git a/drawer-groups/Classes/info.php b/drawer-groups/Classes/info.php
new file mode 100644
index 0000000..f0be6ef
--- /dev/null
+++ b/drawer-groups/Classes/info.php
@@ -0,0 +1,15 @@
+
+<?php
+
+
+define('STUDENTS', ['Bert Lorenzo',     'Buscema Antonio',          'Carbonati Davide',
+                    'Cella Marco',      "D'Augelli Mario",          'Dumitru Adrian',
+                    'Faoro Claudio',    'Ferrero-Merlino Leonardo', 'Fornaro Roberto',
+                    'Gomes Anielle',    'Gregoricchio Matteo',      'Iacobelli Sara',
+                    'Laurenti Diana',   'Linari Matteo',            'Pietrapertosa Fabio',
+                    'Presutti Edoardo', 'Reale Andrea',             'Revelli Ruben',
+                    'Sacchet Gabriele', 'Sartori Alessandro',       'Sinatra Gianpaolo',
+                    'Soncin Erika',     'Vellano Marco',            'Velocci Giuseppe',
+                    'Schutt Daniele',   'Lo Presti Ilaria',         'Morales Yusdel',
+                    'Mason Alessandro'
+                    ]);
\ No newline at end of file
diff --git a/drawer-groups/index.php b/drawer-groups/index.php
new file mode 100644
index 0000000..662020a
--- /dev/null
+++ b/drawer-groups/index.php
@@ -0,0 +1,46 @@
+
+<?php
+
+require_once 'Classes/Drawer.php';
+require_once 'Classes/info.php';
+
+
+$drawer = new Drawer(STUDENTS);
+?>
+
+
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta http-equiv="X-UA-Compatible" content="ie=edge">
+    <title>Document</title>
+</head>
+<body>
+    <h1 align="center">Groups</h1>
+    <div style="display: flex; justify-content: center; margin-top: 5%;">
+        <form method="post">
+            <input type="text" name="groupsMembers" placeholder="number of groups' members" required>
+            <input type="submit" name="groupsButton" value="Make groups!">
+        </form>
+    </div>
+    <div style="display: flex; justify-content: center; margin-top: 2%;">
+        <?php
+            if ($_SERVER['REQUEST_METHOD'] == 'POST')
+            {
+                $groups = $drawer->makeGroups($_POST['groupsMembers']);
+
+                foreach($groups as $key => $group)
+                {
+                    echo '<br><br><br><br>Group ' . $key ;
+
+                    foreach($group as $key => $member)
+                        echo '<br>- ' . $member;
+                }
+            }
+        ?>
+    </div>
+</body>
+</html>
+