diff --git a/.idea/misc.xml b/.idea/misc.xml
index 0548357..1f014b5 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,4 +1,3 @@
-<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
diff --git a/.idea/modules.xml b/.idea/modules.xml
index 19d1c08..5537ffa 100644
--- a/.idea/modules.xml
+++ b/.idea/modules.xml
@@ -3,6 +3,7 @@
   <component name="ProjectModuleManager">
     <modules>
       <module fileurl="file://$PROJECT_DIR$/.idea/UML实践作业.iml" filepath="$PROJECT_DIR$/.idea/UML实践作业.iml" />
+      <module fileurl="file://$PROJECT_DIR$/_01/_01.iml" filepath="$PROJECT_DIR$/_01/_01.iml" />
       <module fileurl="file://$PROJECT_DIR$/_02/_02.iml" filepath="$PROJECT_DIR$/_02/_02.iml" />
     </modules>
   </component>
diff --git a/_02/src/Calculator.java b/_02/src/Calculator.java
index caf5a44..677ed57 100644
--- a/_02/src/Calculator.java
+++ b/_02/src/Calculator.java
@@ -6,6 +6,7 @@ public class Calculator {
         return num1 + num2;
     }
 
+
     // 减法
     public static double subtract(double num1, double num2) {
         return num1 - num2;