diff --git a/Program.cs b/Program.cs
index 9a3d197..f41270e 100644
--- a/Program.cs
+++ b/Program.cs
@@ -2,4 +2,4 @@
 //using Programmation_objet_TLESIO21.TD2;
 using Programmation_objet_TLESIO21.TD3;
 
-Td3.Launch();
+TD4.Launch();
diff --git a/TD3/TD3.cs b/TD3/TD3.cs
index 4514d5b..07795dc 100644
--- a/TD3/TD3.cs
+++ b/TD3/TD3.cs
@@ -7,7 +7,7 @@ using Programmation_objet_TLESIO21.TD3.fleuriste;
 
 
 namespace Programmation_objet_TLESIO21.TD3 {
-    public static class Td3 {
+    public static class TD4 {
 
         public static void Exo1_1() {
             Compte c1 = new Compte();
diff --git a/TD4/Collaborateur.cs b/TD4/Collaborateur.cs
new file mode 100644
index 0000000..d4420bd
--- /dev/null
+++ b/TD4/Collaborateur.cs
@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Programmation_objet_TLESIO21.TD4 {
+    public class Collaborateur {
+        private readonly String NOM;
+        private String DateNaissance;
+
+        public Collaborateur(String nom, String birthdate) {
+            this.NOM = nom;
+            this.DateNaissance = birthdate;
+        }
+
+        public virtual double getSalaire() {
+            return .0;
+        }
+    }
+}
diff --git a/TD4/Commercial.cs b/TD4/Commercial.cs
new file mode 100644
index 0000000..0859a65
--- /dev/null
+++ b/TD4/Commercial.cs
@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Programmation_objet_TLESIO21.TD4 {
+    public class Commercial : Collaborateur {
+        private int SalaireBase;
+        private int ChiffreAffaire;
+        private readonly double T2 = 1.1;
+
+        public Commercial(String nom, String birthdate, int salaireBase, int chiffreAffaire) : base(nom, birthdate) {
+            this.SalaireBase = salaireBase;
+            this.ChiffreAffaire = chiffreAffaire;
+        }
+
+        public override double getSalaire() {
+            return this.SalaireBase + this.ChiffreAffaire * T2;
+        }
+
+
+    }
+}
diff --git a/TD4/Employe.cs b/TD4/Employe.cs
new file mode 100644
index 0000000..684e47c
--- /dev/null
+++ b/TD4/Employe.cs
@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Programmation_objet_TLESIO21.TD4 {
+    public class Employe : Collaborateur {
+        private int TauxHoraire;
+        private int NbHeures;
+        private readonly double T1 = 1.1;
+
+        public Employe(String nom, String birthdate, int tauxHoraire, int nbHeures) : base(nom, birthdate) {
+            this.TauxHoraire = tauxHoraire;
+            this.NbHeures = nbHeures;
+        }
+
+        public override double getSalaire() {
+            double salaire = 0;
+
+            if(this.NbHeures > 35) {
+                salaire += (this.NbHeures - 35) * this.TauxHoraire * T1;
+            }
+
+            salaire += this.NbHeures * this.TauxHoraire;
+
+            return salaire;
+        }
+
+
+    }
+}
diff --git a/TD4/Manager.cs b/TD4/Manager.cs
new file mode 100644
index 0000000..3fcc776
--- /dev/null
+++ b/TD4/Manager.cs
@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Programmation_objet_TLESIO21.TD4 {
+    public class Manager : Collaborateur {
+        private int SalaireBase;
+        private int Prime;
+
+        public Manager(String nom, String birthdate, int salaireBase, int prime) : base(nom, birthdate) {
+            this.SalaireBase = salaireBase;
+            this.Prime = prime;
+        }
+
+        public override double getSalaire() {
+            return this.SalaireBase + this.Prime;
+        }
+
+
+
+
+    }
+}
diff --git a/TD4/TD4.cs b/TD4/TD4.cs
new file mode 100644
index 0000000..b92efbc
--- /dev/null
+++ b/TD4/TD4.cs
@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Programmation_objet_TLESIO21.TD3.fleuriste;
+
+
+namespace Programmation_objet_TLESIO21.TD4 {
+    public static class TD4 {
+        public static void Exo1() {
+            TabCollaborateur tab = new TabCollaborateur();
+            Employe e1 = new Employe("Lejaune", "13051956", 20, 30);
+            Employe e2 = new Employe("LeBlanc", "20051970", 15, 100);
+            Manager m1 = new Manager("LeRouge", "14011998", 2500, 150);
+            Manager m2 = new Manager("LeVert", "29101987", 3000, 200);
+            Commercial c1 = new Commercial("LeNoir", "29011987", 4000, 30000);
+            Commercial c2 = new Commercial("LeViolet", "29011987", 3000, 30000);
+            tab.Add(c1);
+            tab.Add(e1);
+            tab.Add(m1);
+            tab.Add(e2);
+            tab.Add(m2);
+            tab.Add(c2);
+            Console.WriteLine("COLLABORATEUR AYANT PLUS HAUT SALAIRE");
+            Console.WriteLine(tab.PlusHautSal());
+            Console.WriteLine("EMPLOYE AYANT PLUS HAUT SALAIRE");
+            Console.WriteLine(tab.PlusHautSal("Employe"));
+            Console.WriteLine("MANAGER AYANT PLUS HAUT SALAIRE");
+            Console.WriteLine(tab.PlusHautSal("Manager"));
+            Console.WriteLine("COMMERCIAL AYANT PLUS HAUT SALAIRE");
+            Console.WriteLine(tab.PlusHautSal("Commercial"));
+            Console.WriteLine("TRI SUR AGE ");
+            tab.Sort();
+            foreach(Collaborateur c in tab)
+                Console.WriteLine(c);
+            Console.WriteLine("TRI SUR SALAIRE ");
+            tab.Sort(new TriSalaire());
+            foreach(Collaborateur c in tab)
+                Console.WriteLine(c)
+        }
+
+        public static void Launch() {
+
+        }
+
+
+    }
+}
\ No newline at end of file
diff --git a/pdf/CM/Cours4C#.pdf b/pdf/CM/Cours4C#.pdf
new file mode 100644
index 0000000..6c19bb2
Binary files /dev/null and b/pdf/CM/Cours4C#.pdf differ
diff --git a/pdf/TD/TD4.pdf b/pdf/TD/TD4.pdf
new file mode 100644
index 0000000..e87a145
Binary files /dev/null and b/pdf/TD/TD4.pdf differ