diff --git a/src/MathExamGenerator.java b/src/MathExamGenerator.java
index 5a173be..172f4d6 100644
--- a/src/MathExamGenerator.java
+++ b/src/MathExamGenerator.java
@@ -1,8 +1,25 @@
-import java.io.*;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
 import java.nio.charset.Charset;
-import java.nio.file.*;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.text.SimpleDateFormat;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+
 
 /**
  * 中小学数学卷子自动生成程序