diff --git a/step1/daan.sh b/step1/daan.sh
index e062b84..a48d21f 100644
--- a/step1/daan.sh
+++ b/step1/daan.sh
@@ -1,4 +1,4 @@
-
+#!/bin/bash
 
 #将答案填写在下方空白区域
 #/**********  Begin  **********/#