diff --git a/Program.cs b/Program.cs
index 19ed946..2673b5a 100644
--- a/Program.cs
+++ b/Program.cs
@@ -34,7 +34,7 @@ class Program {
                     break;
                 case 4:
                     Console.Clear();
-
+                    LetterSwap();
                     Pausa();
                     break;
                 default:
@@ -105,7 +105,7 @@ class Program {
         return ritorno;
     }
 
-    static void Submenu(){
+    static void Submenu() {
         Console.Clear();
         string frase, input;
         int scelta;
@@ -122,7 +122,7 @@ class Program {
             Console.WriteLine("1. Converti in minuscolo");
             Console.WriteLine("2. Converti in maiuscolo");
             Console.WriteLine("3. Sostituisci \'.\' con \\n");
-            Console.WriteLine("0. Esci");
+            Console.WriteLine("0. Torna al menù precedente");
             Console.Write("Scelta: ");
             scelta = Convert.ToInt32(Console.ReadLine());
 
@@ -158,4 +158,42 @@ class Program {
         }
         while (scelta != 0);
     }
+
+    static void LetterSwap() {
+        string input, stringa1, stringa2, stringa3;
+        int numeroLettere, i, j = 0;
+
+        Console.Write("Inserire una frase: ");
+        input = Console.ReadLine();
+        Console.Write("Inserire il numero di lettere da scambiare: ");
+        numeroLettere = Convert.ToInt32(Console.ReadLine());
+
+
+        char[] array1 = new char[numeroLettere];
+        char[] array2 = new char[input.Length - numeroLettere * 2];
+        char[] array3 = new char[numeroLettere];
+
+        for (i = 0; i < numeroLettere; i++) {
+            array1[j] = input[i];
+            j++;
+        }
+
+        stringa1 = string.Join("", array1);
+
+        j = 0;
+        for (; i < input.Length - numeroLettere; i++) {
+            array2[j] = input[i];
+            j++;
+        }
+        stringa2 = string.Join("", array2);
+
+        j = 0;
+        for (; i < input.Length; i++) {
+            array3[j] = input[i];
+            j++;
+        }
+        stringa3 = string.Join("", array3);
+
+        Console.WriteLine($"La frase con le lettere scambiate è: {stringa3}{stringa2}{stringa1}");
+    }
 }
diff --git a/bin/Debug/net9.0/strings_1.dll b/bin/Debug/net9.0/strings_1.dll
index 462270c..59e027a 100644
Binary files a/bin/Debug/net9.0/strings_1.dll and b/bin/Debug/net9.0/strings_1.dll differ
diff --git a/bin/Debug/net9.0/strings_1.pdb b/bin/Debug/net9.0/strings_1.pdb
index 3ec9fdf..6f00e0b 100644
Binary files a/bin/Debug/net9.0/strings_1.pdb and b/bin/Debug/net9.0/strings_1.pdb differ
diff --git a/obj/Debug/net9.0/ref/strings_1.dll b/obj/Debug/net9.0/ref/strings_1.dll
index 0daa1d3..70e8ae3 100644
Binary files a/obj/Debug/net9.0/ref/strings_1.dll and b/obj/Debug/net9.0/ref/strings_1.dll differ
diff --git a/obj/Debug/net9.0/refint/strings_1.dll b/obj/Debug/net9.0/refint/strings_1.dll
index 0daa1d3..70e8ae3 100644
Binary files a/obj/Debug/net9.0/refint/strings_1.dll and b/obj/Debug/net9.0/refint/strings_1.dll differ
diff --git a/obj/Debug/net9.0/strings_1.AssemblyInfo.cs b/obj/Debug/net9.0/strings_1.AssemblyInfo.cs
index b800bb9..b0df734 100644
--- a/obj/Debug/net9.0/strings_1.AssemblyInfo.cs
+++ b/obj/Debug/net9.0/strings_1.AssemblyInfo.cs
@@ -13,7 +13,7 @@ using System.Reflection;
 [assembly: System.Reflection.AssemblyCompanyAttribute("strings_1")]
 [assembly: System.Reflection.AssemblyConfigurationAttribute("Debug")]
 [assembly: System.Reflection.AssemblyFileVersionAttribute("1.0.0.0")]
-[assembly: System.Reflection.AssemblyInformationalVersionAttribute("1.0.0+31b87989795cdfc8100c8dabff5d2ce0a03e2e16")]
+[assembly: System.Reflection.AssemblyInformationalVersionAttribute("1.0.0+ccf2dfdddbb4c94a19e023f37e05913e2545cff7")]
 [assembly: System.Reflection.AssemblyProductAttribute("strings_1")]
 [assembly: System.Reflection.AssemblyTitleAttribute("strings_1")]
 [assembly: System.Reflection.AssemblyVersionAttribute("1.0.0.0")]
diff --git a/obj/Debug/net9.0/strings_1.AssemblyInfoInputs.cache b/obj/Debug/net9.0/strings_1.AssemblyInfoInputs.cache
index dc3e843..e14dedc 100644
--- a/obj/Debug/net9.0/strings_1.AssemblyInfoInputs.cache
+++ b/obj/Debug/net9.0/strings_1.AssemblyInfoInputs.cache
@@ -1 +1 @@
-260a48af17a58db4c14ce60e5b496bd92beb2181e1f61cd574e399e1f1445cf0
+d4a8bf2719c6ab479c0f2d6052891a9062b0f984718d04ce460f7e151ca9bbeb
diff --git a/obj/Debug/net9.0/strings_1.dll b/obj/Debug/net9.0/strings_1.dll
index 462270c..59e027a 100644
Binary files a/obj/Debug/net9.0/strings_1.dll and b/obj/Debug/net9.0/strings_1.dll differ
diff --git a/obj/Debug/net9.0/strings_1.pdb b/obj/Debug/net9.0/strings_1.pdb
index 3ec9fdf..6f00e0b 100644
Binary files a/obj/Debug/net9.0/strings_1.pdb and b/obj/Debug/net9.0/strings_1.pdb differ