diff --git a/go-demo-4/main.go b/go-demo-4/main.go
index 598fd88..13b8aea 100644
--- a/go-demo-4/main.go
+++ b/go-demo-4/main.go
@@ -10,6 +10,9 @@ import (
 )
 
 func main() {
+	// fmt.Println(output.Sum(100, 42))
+	// fmt.Println(output.Sum(10.7, 3.14))
+	// fmt.Println(output.Sum("Hello ", "world!"))
 	fmt.Println("__Менеджер паролей__")
 	vault := account.NewVault(files.NewJsonDb("data.json"))
 Menu:
diff --git a/go-demo-4/output/errors.go b/go-demo-4/output/errors.go
index 1414dfc..4c72d6e 100644
--- a/go-demo-4/output/errors.go
+++ b/go-demo-4/output/errors.go
@@ -14,3 +14,13 @@ func PrintError(value any) {
 		color.Red("Неизвестный тип ошибки")
 	}
 }
+
+// Generic
+func Sum[T int | float32 | float64 | string](a, b T) T {
+	return a + b
+}
+
+// Generic structs
+type List[T any] struct {
+	elements []T
+}