diff --git a/README.md b/README.md
index 982ccd8..dbf6d4c 100644
--- a/README.md
+++ b/README.md
@@ -89,6 +89,17 @@ You can save solution by setting `leetcode-save-solutions`:
 (setq leetcode-directory "~/leetcode")
 ```
 
+If you want to have some code before your solution, which may make auto-completion work better but shouldn't been submitted, you can customize `leetcode-ignore-region` to ignore lines in your code. For example, suppose you have a `common.h` and some custom definations, and `leetcode-ignore-region` is set to `'("" "// start code")`, only code below `// start code` will be submitted:
+
+```c++
+#include "common.h"
+... your custom definations ...
+// start code
+
+class Solution {
+    ......
+```
+
 # Work with Org Mode
 
 `leetcode-show-problem-by-slug` will let you put to org files with a link in this format to show the question after the *leetcode* buffer is load like [elisp:(leetcode-show-problem-by-slug (leetcode--slugify-title "ZigZag Conversion"))]
diff --git a/leetcode.el b/leetcode.el
index f916a74..095f151 100644
--- a/leetcode.el
+++ b/leetcode.el
@@ -98,7 +98,7 @@
 (defcustom leetcode-prefer-language "python3"
   "LeetCode programming language.
 c, cpp, csharp, golang, java, javascript, typescript, kotlin, php, python,
-python3, ruby, rust, scala, swift."
+python3, racket, ruby, rust, scala, swift."
   :group 'leetcode
   :type 'string)
 
@@ -123,6 +123,14 @@ mysql, mssql, oraclesql."
   :group 'leetcode
   :type 'boolean)
 
+(defcustom leetcode-ignore-region '("" "")
+  "If it's '(MARK1 MARK2), and none of them is \"\", ignore code between lines
+ starting with \"MARK1\" and \"MARK2\" when submitting code. If only MARK1 is
+ \"\", ignore code before MARK2. If only MARK2 is \"\", ignore code from MARK1.
+ If both are \"\", ignore nothing."
+  :group 'leetcode
+  :type '(list string string))
+
 (cl-defstruct leetcode-user
   "A LeetCode User.
 The object with following attributes:
@@ -194,7 +202,7 @@ Default is programming language.")
     ("mysql" . ".sql") ("mssql" . ".sql") ("oraclesql" . ".sql"))
   "LeetCode programming language suffixes.
 c, cpp, csharp, golang, java, javascript, typescript, kotlin, php, python,
-python3, ruby, rust, scala, swift, mysql, mssql, oraclesql.")
+python3, racket, ruby, rust, scala, swift, mysql, mssql, oraclesql.")
 
 (defvar leetcode--filter-regex nil "Filter rows by regex.")
 (defvar leetcode--filter-tag nil "Filter rows by tag.")
@@ -800,6 +808,30 @@ see: https://github.com/skeeto/emacs-aio/issues/3."
     (buffer-substring-no-properties
      (point-min) (point-max))))
 
+(defun leetcode--code-buffer-content (buf)
+  "Get code content without text properties of BUF, taking `leetcode-ignore-region'
+into consideration."
+  (let ((code (leetcode--buffer-content buf)))
+    (if (not (equal leetcode-ignore-region '("" "")))
+        (let* ((lines (string-lines code))
+               (mark-start (car leetcode-ignore-region))
+               (mark-end (car (cdr leetcode-ignore-region)))
+               (result '())
+               (ignore (equal mark-start "")))
+          (dolist (line lines result)
+            (cond ((and (not (equal mark-start "")) (string-prefix-p mark-start line))
+                   (setq ignore t)
+                   (push "" result))
+                  ((and (not (equal mark-end "")) (string-prefix-p mark-end line))
+                   (setq ignore nil)
+                   (push "" result))
+                  (ignore
+                   (push "" result))
+                  ((not ignore)
+                   (push line result))))
+          (string-join (reverse result) "\n"))
+      (code))))
+
 (defun leetcode--get-slug-title (code-buf)
   "Get slug title before try or submit with CODE-BUF.
 LeetCode require slug-title as the request parameters."
@@ -819,7 +851,7 @@ LeetCode require slug-title as the request parameters."
          (backend-id (leetcode-problem-backend-id problem))
          (testcase-buf (get-buffer (leetcode--testcase-buffer-name problem-id)))
          (result (aio-await (leetcode--api-try backend-id slug-title
-                                               (leetcode--buffer-content code-buf)
+                                               (leetcode--code-buffer-content code-buf)
                                                (leetcode--buffer-content testcase-buf)))))
     (if-let ((error-info (plist-get (car result) :error)))
         (progn
@@ -997,7 +1029,7 @@ STATUS_CODE has following possible value:
   (interactive)
   (leetcode--loading-mode t)
   (let* ((code-buf (current-buffer))
-         (code (leetcode--buffer-content code-buf))
+         (code (leetcode--code-buffer-content code-buf))
          (slug-title (leetcode--get-slug-title code-buf))
          (problem (leetcode--get-problem slug-title))
          (problem-id (leetcode-problem-id problem))