diff --git a/.gitignore b/.gitignore
index 1a577dc..99c0d65 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,7 +20,6 @@ main
 /coverage*
 /test.*
 /config.yml
-*.eduoj-backend
 
 /testing_requests
 /EduOJBackend
diff --git a/app/controller/problem_set.go b/app/controller/problem_set.go
index a0a9f08..8ff75df 100644
--- a/app/controller/problem_set.go
+++ b/app/controller/problem_set.go
@@ -20,7 +20,7 @@ func CreateProblemSet(c echo.Context) error {
 	req := request.CreateProblemSetRequest{}
 	err, ok := utils.BindAndValidate(&req, c)
 	if !ok {
-		return err //aaa
+		return err
 	}
 	class := models.Class{}
 	if err := base.DB.First(&class, c.Param("id")).Error; err != nil {
diff --git a/main.go b/main.go
index 4dc4292..4beb417 100644
--- a/main.go
+++ b/main.go
@@ -18,7 +18,7 @@ func main() {
 	parse()
 	if len(args) < 1 {
 		log.Fatal("Please specific a command to run.")
-		// TODO: output usage aa
+		// TODO: output usage
 		os.Exit(-1)
 	}
 	switch args[0] {