diff --git a/lab20.py b/lab20.py
new file mode 100644
index 0000000..118d9ef
--- /dev/null
+++ b/lab20.py
@@ -0,0 +1,15 @@
+hat_list = [1, 2, 3, 4, 5]
+
+# passo 1
+
+hat_list[2] = int(input("Inserisci il nuovo numero centrale: "))
+
+# passo 2
+
+del hat_list[-1]
+
+# passo 3
+
+print("Lunghezza: ",len(hat_list))
+
+print(hat_list)
\ No newline at end of file