diff --git a/diy4.py b/diy4.py
new file mode 100644
index 0000000..c472334
--- /dev/null
+++ b/diy4.py
@@ -0,0 +1,19 @@
+i=3
+username = "python"
+userpassword = "123456"
+while True:
+    if i>0:
+        i=i-1
+        name = input("请输入用户名:")
+        password = input("请输入密码:")
+        if name == username and password == userpassword:
+            print("登录成功!")
+            break
+        elif name!=username:
+            print("用户名错误!请重新输入")
+        else:
+            print("密码错误!请重新输入")
+    else:
+        print("嘿嘿嘿，小黑子")
+        exit()
+print("欢迎来到贝尔编程!")
\ No newline at end of file