diff --git a/Program.cs b/Program.cs
index a9b0ea4..140c7de 100644
--- a/Program.cs
+++ b/Program.cs
@@ -8,7 +8,7 @@ class Program {
     static void Menu() {
         Console.Clear();
         int scelta;
-        string stringa;
+        string stringa1, stringa2;
         do {
             Console.WriteLine("Inserire un'opzione:");
             Console.WriteLine("1. Alterna i caratteri");
@@ -26,7 +26,14 @@ class Program {
                     break;
                 case 1:
                     Console.Clear();
-                    AlternaCaratteri();
+                    stringa1 = Input();
+                    stringa2 = Input();
+                    if (Controllo(stringa1, stringa2)) {
+                        Console.WriteLine(AlternaCaratteri(stringa1, stringa2));
+                    }
+                    else {
+                        Console.WriteLine("Errore: le due stringhe devono essere lunghe uguali");
+                    }
                     Pausa();
                     break;
                 case 2:
@@ -75,32 +82,27 @@ class Program {
         return Console.ReadLine();
     }
 
-    static void AlternaCaratteri() {
-        string stringa1 = Input();
-        string stringa2 = Input();
-        bool stringa1Max = stringa1.Length > stringa2.Length;
-        int lunghezza = stringa1Max ? stringa1.Length : stringa2.Length;
-
-        for (int i = 0; i < lunghezza; i++) {
-            if (stringa1Max) {
-                if (i < stringa2.Length) {
-                    Console.Write($"{stringa1[i]}{stringa2[i]}");
-                }
-                else {
-                    Console.Write(stringa1[i]);
-                }
-            }
-            else {
-                if (i < stringa1.Length) {
-                    Console.Write($"{stringa1[i]}{stringa2[i]}");
-                }
-                else {
-                    Console.Write(stringa2[i]);
-                }
-            }
-
+    static bool Controllo(string p_stringa1, string p_stringa2) {
+        bool ritorno;
+        if (p_stringa1.Length == p_stringa2.Length) {
+            ritorno = true;
         }
-        Console.WriteLine();
+        else {
+            ritorno = false;
+        }
+
+        return ritorno;
+
+    }
+
+    static string AlternaCaratteri(string p_stringa1, string p_stringa2) {
+        string ritorno = "";
+
+        for (int i = 0; i < p_stringa1.Length; i++) {
+            ritorno = string.Concat(ritorno, p_stringa1[i], p_stringa2[i]);
+        }
+
+        return ritorno;
     }
 
     static string Codifica() {
diff --git a/bin/Debug/net9.0/strings_3.dll b/bin/Debug/net9.0/strings_3.dll
index 2ffa3d7..82f117b 100644
Binary files a/bin/Debug/net9.0/strings_3.dll and b/bin/Debug/net9.0/strings_3.dll differ
diff --git a/bin/Debug/net9.0/strings_3.pdb b/bin/Debug/net9.0/strings_3.pdb
index 692d0d0..9c83287 100644
Binary files a/bin/Debug/net9.0/strings_3.pdb and b/bin/Debug/net9.0/strings_3.pdb differ
diff --git a/obj/Debug/net9.0/ref/strings_3.dll b/obj/Debug/net9.0/ref/strings_3.dll
index 1cb1859..e6af496 100644
Binary files a/obj/Debug/net9.0/ref/strings_3.dll and b/obj/Debug/net9.0/ref/strings_3.dll differ
diff --git a/obj/Debug/net9.0/refint/strings_3.dll b/obj/Debug/net9.0/refint/strings_3.dll
index 1cb1859..e6af496 100644
Binary files a/obj/Debug/net9.0/refint/strings_3.dll and b/obj/Debug/net9.0/refint/strings_3.dll differ
diff --git a/obj/Debug/net9.0/strings_3.AssemblyInfo.cs b/obj/Debug/net9.0/strings_3.AssemblyInfo.cs
index 31f574e..8fd9189 100644
--- a/obj/Debug/net9.0/strings_3.AssemblyInfo.cs
+++ b/obj/Debug/net9.0/strings_3.AssemblyInfo.cs
@@ -13,10 +13,10 @@ using System.Reflection;
 [assembly: System.Reflection.AssemblyCompanyAttribute("strings_3")]
 [assembly: System.Reflection.AssemblyConfigurationAttribute("Debug")]
 [assembly: System.Reflection.AssemblyFileVersionAttribute("1.0.0.0")]
-[assembly: System.Reflection.AssemblyInformationalVersionAttribute("1.0.0+d29d204ee494646ce5094700197a900b05cc44aa")]
+[assembly: System.Reflection.AssemblyInformationalVersionAttribute("1.0.0+8d0599b65c9adc395c7a863ae0c292a2ea4126c5")]
 [assembly: System.Reflection.AssemblyProductAttribute("strings_3")]
 [assembly: System.Reflection.AssemblyTitleAttribute("strings_3")]
 [assembly: System.Reflection.AssemblyVersionAttribute("1.0.0.0")]
 
-// Generato dalla classe WriteCodeFragment di MSBuild.
+// Generated by the MSBuild WriteCodeFragment class.
 
diff --git a/obj/Debug/net9.0/strings_3.AssemblyInfoInputs.cache b/obj/Debug/net9.0/strings_3.AssemblyInfoInputs.cache
index 96b12b6..b1f6654 100644
--- a/obj/Debug/net9.0/strings_3.AssemblyInfoInputs.cache
+++ b/obj/Debug/net9.0/strings_3.AssemblyInfoInputs.cache
@@ -1 +1 @@
-cbb955859c30d97643b375ba8ca1883b485f554c16cef8a828a4aa0bf8968236
+2a1edca03dfab0d51deb008cf18acd10fc7a6338349d06d54d7fc8dfb3ff671e
diff --git a/obj/Debug/net9.0/strings_3.dll b/obj/Debug/net9.0/strings_3.dll
index 2ffa3d7..82f117b 100644
Binary files a/obj/Debug/net9.0/strings_3.dll and b/obj/Debug/net9.0/strings_3.dll differ
diff --git a/obj/Debug/net9.0/strings_3.pdb b/obj/Debug/net9.0/strings_3.pdb
index 692d0d0..9c83287 100644
Binary files a/obj/Debug/net9.0/strings_3.pdb and b/obj/Debug/net9.0/strings_3.pdb differ