diff --git a/src/problem.java b/src/problem.java
new file mode 100644
index 0000000..f11f6b5
--- /dev/null
+++ b/src/problem.java
@@ -0,0 +1,120 @@
+import java.util.Random;
+import java.util.Scanner;
+import java.util.*;
+import java.io.IOException;
+
+public class problem {
+    String level;
+    String name;
+    public void display(){
+        try {
+            new ProcessBuilder("clear").inheritIO().start().waitFor();
+        } catch (IOException | InterruptedException e) {
+            //e.printStackTrace();
+        }
+//        try {
+//            Runtime.getRuntime().exec("cmd /c cls").waitFor();
+//        } catch (IOException | InterruptedException e) {
+//            e.printStackTrace();
+//        }
+        System.out.println("=== 中小学数学卷子自动生成程序 ===");
+    }
+    public void start(User user) {
+        level = user.level;
+        name = user.username;
+        while (true) {
+            display();
+            System.out.println("欢迎你 " + user.username + " " + level);
+            System.out.println("输入1开始出题");
+            System.out.println("输入2切换出题年级");
+            System.out.println("输入-1退出登录，返回开始界面");
+            Scanner sc = new Scanner(System.in);
+            int flag=0;
+            while (true) {
+                String str = sc.next();
+                try {
+                    flag=Integer.parseInt(str);
+                } catch (NumberFormatException e) {
+                    flag=0;
+                }
+                if (flag == 1 || flag ==2 || flag ==-1)
+                    break;
+                else
+                    System.out.println("请输入正确的操作");
+            }
+            if (flag == 1) {
+                if (f1() == 0)
+                    continue;
+            }
+            if (flag == 2) {
+                if (f2() == 0)
+                    continue;
+            }
+            if (flag == -1)
+                break;
+        }
+    }
+
+    public int f1() {
+        System.out.println("正在为" + level + "出题");
+        System.out.println("请在10-30的范围内输入出题数目，输入-1返回操作界面");
+        Scanner sc = new Scanner(System.in);
+        int num=0;
+        while (true) {
+            String str = sc.next();
+            try {
+                num=Integer.parseInt(str);
+            } catch (NumberFormatException e) {
+                num=0;
+            }
+            if (num == -1)
+                break;
+            if (num >= 10 && num <= 30)
+                break;
+            else
+                System.out.println("请输入10-30范围的出题数");
+        }
+        if (num == -1) {
+            return 0;
+        }
+        if (level.equals("小学")) {
+            Primaryproblem p1 = new Primaryproblem();
+            p1.start(num,name);
+        } else if (level.equals("初中")) {
+            Middleproblem m1 = new Middleproblem();
+            m1.start(num,name);
+        } else if (level.equals("高中")) {
+            Highproblem h1 = new Highproblem();
+            h1.start(num,name);
+        }
+        System.out.println("已出题完成,输入-1返回操作界面");
+        while (!sc.next().equals("-1")) {
+            continue;
+        }
+        return 0;
+    }
+
+    public int f2() {
+        System.out.println("请输入想要切换的出题年级,输入-1返回操作界面");
+        String num;
+        Scanner sc = new Scanner(System.in);
+        while (true) {
+            num = sc.next();
+            if (num.equals("-1"))
+                break;
+            if (num.equals("初中") || (num.equals("小学")) || (num.equals("高中")))
+                break;
+            else
+                System.out.println("请输入小学、初中和高中三个选项中的一个");
+        }
+        if (num.equals("-1")) {
+            return 0;
+        }
+        level = num;
+        System.out.println("已成功修改出题年级为" + level + ",输入-1返回操作界面");
+        while (!sc.next().equals("-1")) {
+            continue;
+        }
+        return 0;
+    }
+}