diff --git a/diy.py b/diy.py
index e6e8e70..c41548f 100644
--- a/diy.py
+++ b/diy.py
@@ -3,8 +3,8 @@
 cost= {'苹果':5.2,'山竹':12.9,'香蕉':2.4,'荔枝':15,'葡萄':9.3,'桂圆':8,'蓝莓':10,'李子':8}
 k=input('请输入水果名称：')
 v=input('请输入水果价钱：')
-# ?补充条件判断:
-    if # ?:
+if k in cost:# ?补充条件判断:
+    if int(v)<cost[k]:# ?:
         # ?更新价钱
         print(k+'降价了，现价'+v+'元')
     else: