diff --git a/judge/ml/collab_filter.py b/judge/ml/collab_filter.py
index 7b3e040..c68daa6 100644
--- a/judge/ml/collab_filter.py
+++ b/judge/ml/collab_filter.py
@@ -65,7 +65,7 @@ class CollabFilter:
         return res
 
     # return a list of pid
-    def problems_neighbors(self, problem, problemset, measure=DOT, limit=None):
+    def problem_neighbors(self, problem, problemset, measure=DOT, limit=None):
         pid = problem.id
         if pid >= len(self.problem_embeddings):
             return None
@@ -74,7 +74,7 @@ class CollabFilter:
         )
         res = []
         for p in problemset:
-            if p.id < len(scores):
-                res.append((scores[p.id], p))
+            if p < len(scores):
+                res.append((scores[p], p))
         res.sort(reverse=True, key=lambda x: x[0])
         return res[:limit]
diff --git a/judge/utils/problems.py b/judge/utils/problems.py
index d20e542..46c846b 100644
--- a/judge/utils/problems.py
+++ b/judge/utils/problems.py
@@ -1,6 +1,8 @@
 from collections import defaultdict
 from math import e
 import os, zipfile
+from datetime import datetime
+import random
 
 from django.conf import settings
 from django.core.cache import cache
@@ -10,6 +12,8 @@ from django.utils import timezone
 from django.utils.translation import gettext as _, gettext_noop
 
 from judge.models import Problem, Submission
+from judge.ml.collab_filter import CollabFilter
+
 
 __all__ = [
     "contest_completed_ids",
@@ -229,3 +233,20 @@ def hot_problems(duration, limit):
 
         cache.set(cache_key, qs, 900)
     return qs
+
+
+def get_related_problems(profile, problem, limit=8):
+    if not profile:
+        return None
+    problemset = Problem.get_visible_problems(profile.user).values_list("id", flat=True)
+    problemset = problemset.exclude(id__in=user_completed_ids(profile))
+    problemset = problemset.exclude(id=problem.id)
+    cf_model = CollabFilter("collab_filter")
+    results = cf_model.problem_neighbors(
+        problem, problemset, CollabFilter.DOT, limit
+    ) + cf_model.problem_neighbors(problem, problemset, CollabFilter.COSINE, limit)
+    results = list(set([i[1] for i in results]))
+    seed = datetime.now().strftime("%d%m%Y")
+    random.Random(seed).shuffle(results)
+    results = results[:limit]
+    return [Problem.objects.get(id=i) for i in results]
diff --git a/judge/views/problem.py b/judge/views/problem.py
index 904d86b..c54b7dd 100644
--- a/judge/views/problem.py
+++ b/judge/views/problem.py
@@ -76,6 +76,7 @@ from judge.utils.problems import (
     hot_problems,
     user_attempted_ids,
     user_completed_ids,
+    get_related_problems,
 )
 from judge.utils.strings import safe_float_or_none, safe_int_or_none
 from judge.utils.tickets import own_ticket_filter
@@ -352,6 +353,10 @@ class ProblemDetail(
         else:
             context["fileio_input"] = None
             context["fileio_output"] = None
+        if not self.in_contest:
+            context["related_problems"] = get_related_problems(
+                self.profile, self.object
+            )
 
         return context
 
diff --git a/locale/vi/LC_MESSAGES/django.po b/locale/vi/LC_MESSAGES/django.po
index 24a3eb2..aeee9b4 100644
--- a/locale/vi/LC_MESSAGES/django.po
+++ b/locale/vi/LC_MESSAGES/django.po
@@ -2,7 +2,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: lqdoj2\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2023-01-28 06:34+0700\n"
+"POT-Creation-Date: 2023-01-28 08:12+0700\n"
 "PO-Revision-Date: 2021-07-20 03:44\n"
 "Last-Translator: Icyene\n"
 "Language-Team: Vietnamese\n"
@@ -2189,7 +2189,7 @@ msgid "judge"
 msgstr "máy chấm"
 
 #: judge/models/submission.py:20 judge/models/submission.py:47
-#: judge/utils/problems.py:116
+#: judge/utils/problems.py:120
 msgid "Accepted"
 msgstr "Accepted"
 
@@ -2218,7 +2218,7 @@ msgid "Runtime Error"
 msgstr "Runtime Error"
 
 #: judge/models/submission.py:27 judge/models/submission.py:41
-#: judge/models/submission.py:55 judge/utils/problems.py:120
+#: judge/models/submission.py:55 judge/utils/problems.py:124
 msgid "Compile Error"
 msgstr "Compile Error"
 
@@ -2509,19 +2509,19 @@ msgstr ""
 msgid "How did you corrupt the interactor path?"
 msgstr "How did you corrupt the custom checker path?"
 
-#: judge/utils/problems.py:117
+#: judge/utils/problems.py:121
 msgid "Wrong"
 msgstr "Sai"
 
-#: judge/utils/problems.py:123
+#: judge/utils/problems.py:127
 msgid "Timeout"
 msgstr "Quá thời gian"
 
-#: judge/utils/problems.py:126
+#: judge/utils/problems.py:130
 msgid "Error"
 msgstr "Lỗi"
 
-#: judge/utils/problems.py:143
+#: judge/utils/problems.py:147
 msgid "Can't pass both queryset and keyword filters"
 msgstr ""
 
@@ -2964,60 +2964,60 @@ msgstr "Chỉnh sửa %s"
 msgid "Pending blogs in %s"
 msgstr "Bài đang đợi duyệt trong %s"
 
-#: judge/views/problem.py:131
+#: judge/views/problem.py:132
 msgid "No such problem"
 msgstr "Không có bài nào như vậy"
 
-#: judge/views/problem.py:132
+#: judge/views/problem.py:133
 #, python-format
 msgid "Could not find a problem with the code \"%s\"."
 msgstr "Không tìm thấy bài tập với mã bài \"%s\"."
 
-#: judge/views/problem.py:199
+#: judge/views/problem.py:200
 #, python-brace-format
 msgid "Editorial for {0}"
 msgstr "Hướng dẫn cho {0}"
 
-#: judge/views/problem.py:203
+#: judge/views/problem.py:204
 #, python-brace-format
 msgid "Editorial for <a href=\"{1}\">{0}</a>"
 msgstr "Hướng dẫn cho <a href=\"{1}\">{0}</a>"
 
-#: judge/views/problem.py:458 templates/contest/contest.html:97
+#: judge/views/problem.py:461 templates/contest/contest.html:97
 #: templates/organization/org-left-sidebar.html:4
 #: templates/user/user-about.html:28 templates/user/user-bookmarks.html:34
 #: templates/user/user-tabs.html:5 templates/user/users-table.html:19
 msgid "Problems"
 msgstr "Bài tập"
 
-#: judge/views/problem.py:846
+#: judge/views/problem.py:835
 msgid "Problem feed"
 msgstr "Bài tập"
 
-#: judge/views/problem.py:1084
+#: judge/views/problem.py:1073
 msgid "Banned from submitting"
 msgstr "Bị cấm nộp bài"
 
-#: judge/views/problem.py:1086
+#: judge/views/problem.py:1075
 msgid ""
 "You have been declared persona non grata for this problem. You are "
 "permanently barred from submitting this problem."
 msgstr "Bạn đã bị cấm nộp bài này."
 
-#: judge/views/problem.py:1109
+#: judge/views/problem.py:1098
 msgid "Too many submissions"
 msgstr "Quá nhiều lần nộp"
 
-#: judge/views/problem.py:1111
+#: judge/views/problem.py:1100
 msgid "You have exceeded the submission limit for this problem."
 msgstr "Bạn đã vượt quá số lần nộp cho bài này."
 
-#: judge/views/problem.py:1190 judge/views/problem.py:1195
+#: judge/views/problem.py:1179 judge/views/problem.py:1184
 #, python-format
 msgid "Submit to %(problem)s"
 msgstr "Nộp bài cho %(problem)s"
 
-#: judge/views/problem.py:1218
+#: judge/views/problem.py:1207
 msgid "Clone Problem"
 msgstr "Nhân bản bài tập"
 
@@ -3189,7 +3189,7 @@ msgid "Submission of %(problem)s by %(user)s"
 msgstr "Bài nộp của %(user)s cho bài %(problem)s"
 
 #: judge/views/submission.py:321 judge/views/submission.py:322
-#: templates/problem/problem.html:173
+#: templates/problem/problem.html:169
 msgid "All submissions"
 msgstr "Tất cả bài nộp"
 
@@ -3683,7 +3683,7 @@ msgid "You have no ticket"
 msgstr "Bạn không có báo cáo"
 
 #: templates/blog/list.html:79 templates/problem/list.html:150
-#: templates/problem/problem.html:399
+#: templates/problem/problem.html:384
 msgid "Clarifications"
 msgstr "Thông báo"
 
@@ -3692,7 +3692,7 @@ msgid "Add"
 msgstr "Thêm mới"
 
 #: templates/blog/list.html:105 templates/problem/list.html:172
-#: templates/problem/problem.html:410
+#: templates/problem/problem.html:395
 msgid "No clarifications have been made at this time."
 msgstr "Không có thông báo nào."
 
@@ -3816,12 +3816,13 @@ msgid "Hide"
 msgstr "Ẩn"
 
 #: templates/comments/list.html:137
+#, python-format
 msgid ""
 "This comment is hidden due to too much negative feedback. Click <a href="
 "\"javascript:comment_show_content(%(id)s)\">here</a> to view it."
 msgstr ""
-"Bình luận bị ẩn vì nhiều phản hồi tiêu cực. Nhấp vào <a href="
-"\"javascript:comment_show_content(%(id)s)\">đây</a> để mở."
+"Bình luận bị ẩn vì nhiều phản hồi tiêu cực. Nhấp vào <a href=\"javascript:"
+"comment_show_content(%(id)s)\">đây</a> để mở."
 
 #: templates/comments/list.html:154
 msgid "There are no comments at the moment."
@@ -4517,7 +4518,7 @@ msgstr "Xem YAML"
 msgid "Autofill testcases"
 msgstr "Tự động điền test"
 
-#: templates/problem/data.html:490 templates/problem/problem.html:281
+#: templates/problem/data.html:490 templates/problem/problem.html:277
 msgid "Problem type"
 msgid_plural "Problem types"
 msgstr[0] "Dạng bài"
@@ -4739,136 +4740,128 @@ msgstr "Bạn có chắc muốn tính điểm lại %(count)d bài nộp?"
 msgid "Rescore all submissions"
 msgstr "Tính điểm lại các bài nộp"
 
-#: templates/problem/problem.html:138
+#: templates/problem/problem.html:134
 msgid "View as PDF"
 msgstr "Xem PDF"
 
-#: templates/problem/problem.html:147 templates/problem/problem.html:157
-#: templates/problem/problem.html:162
+#: templates/problem/problem.html:143 templates/problem/problem.html:153
+#: templates/problem/problem.html:158
 msgid "Submit solution"
 msgstr "Nộp bài"
 
-#: templates/problem/problem.html:150
+#: templates/problem/problem.html:146
 #, python-format
 msgid "%(counter)s submission left"
 msgid_plural "%(counter)s submissions left"
 msgstr[0] "Còn %(counter)s lần nộp"
 
-#: templates/problem/problem.html:158
+#: templates/problem/problem.html:154
 msgid "0 submissions left"
 msgstr "Còn 0 lần nộp"
 
-#: templates/problem/problem.html:170
+#: templates/problem/problem.html:166
 msgid "My submissions"
 msgstr "Bài nộp của tôi"
 
-#: templates/problem/problem.html:174
+#: templates/problem/problem.html:170
 msgid "Best submissions"
 msgstr "Các bài nộp tốt nhất"
 
-#: templates/problem/problem.html:178
+#: templates/problem/problem.html:174
 msgid "Read editorial"
 msgstr "Xem hướng dẫn"
 
-#: templates/problem/problem.html:183
+#: templates/problem/problem.html:179
 msgid "Manage tickets"
 msgstr "Xử lý báo cáo"
 
-#: templates/problem/problem.html:187
+#: templates/problem/problem.html:183
 msgid "Edit problem"
 msgstr "Chỉnh sửa bài"
 
-#: templates/problem/problem.html:189
+#: templates/problem/problem.html:185
 msgid "Edit test data"
 msgstr "Chỉnh sửa test"
 
-#: templates/problem/problem.html:194
+#: templates/problem/problem.html:190
 msgid "My tickets"
 msgstr "Báo cáo của tôi"
 
-#: templates/problem/problem.html:202
+#: templates/problem/problem.html:198
 msgid "Manage submissions"
 msgstr "Quản lý bài nộp"
 
-#: templates/problem/problem.html:208
+#: templates/problem/problem.html:204
 msgid "Clone problem"
 msgstr "Nhân bản bài"
 
-#: templates/problem/problem.html:215
+#: templates/problem/problem.html:211
 msgid "Points:"
 msgstr "Điểm:"
 
-#: templates/problem/problem.html:218 templates/problem/problem.html:220
+#: templates/problem/problem.html:214 templates/problem/problem.html:216
 msgid "(partial)"
 msgstr "(thành phần)"
 
-#: templates/problem/problem.html:225
+#: templates/problem/problem.html:221
 msgid "Time limit:"
 msgstr "Thời gian:"
 
-#: templates/problem/problem.html:237
+#: templates/problem/problem.html:233
 msgid "Memory limit:"
 msgstr "Bộ nhớ:"
 
-#: templates/problem/problem.html:249 templates/problem/raw.html:67
+#: templates/problem/problem.html:245 templates/problem/raw.html:67
 #: templates/submission/status-testcases.html:160
 msgid "Input:"
 msgstr "Input:"
 
-#: templates/problem/problem.html:251 templates/problem/raw.html:67
+#: templates/problem/problem.html:247 templates/problem/raw.html:67
 msgid "stdin"
 msgstr "bàn phím"
 
-#: templates/problem/problem.html:255 templates/problem/raw.html:70
+#: templates/problem/problem.html:251 templates/problem/raw.html:70
 #: templates/submission/status-testcases.html:164
 msgid "Output:"
 msgstr "Output:"
 
-#: templates/problem/problem.html:256 templates/problem/raw.html:70
+#: templates/problem/problem.html:252 templates/problem/raw.html:70
 msgid "stdout"
 msgstr "màn hình"
 
-#: templates/problem/problem.html:266
+#: templates/problem/problem.html:262
 msgid "Author:"
 msgid_plural "Authors:"
 msgstr[0] "Tác giả:"
 
-#: templates/problem/problem.html:294
+#: templates/problem/problem.html:290
 msgid "Allowed languages"
 msgstr "Ngôn ngữ cho phép"
 
-#: templates/problem/problem.html:302
+#: templates/problem/problem.html:298
 #, python-format
 msgid "No %(lang)s judge online"
 msgstr "Không có máy chấm cho %(lang)s"
 
-#: templates/problem/problem.html:314
+#: templates/problem/problem.html:310
 #: templates/status/judge-status-table.html:2
 msgid "Judge"
 msgid_plural "Judges"
 msgstr[0] "Máy chấm"
 
-#: templates/problem/problem.html:332
+#: templates/problem/problem.html:328
 msgid "none available"
 msgstr "Bài này chưa có máy chấm"
 
-#: templates/problem/problem.html:344
+#: templates/problem/problem.html:340
 #, python-format
 msgid "This problem has %(length)s clarification(s)"
 msgstr "Bài này có %(length)s thông báo"
 
-#: templates/problem/problem.html:374
+#: templates/problem/problem.html:370
 msgid "Request clarification"
 msgstr "Yêu cầu làm rõ đề"
 
-#: templates/problem/problem.html:387
-msgid "View comments"
-msgstr "Xem bình luận"
-
-#: templates/problem/problem.html:389
-msgid "Be the first to comment"
-msgstr "Bình luận đầu tiên"
-
 #: templates/problem/raw.html:73
 msgid "Time Limit:"
 msgstr "Giới hạn thời gian:"
@@ -4881,6 +4874,10 @@ msgstr "Giới hạn bộ nhớ:"
 msgid "Last unsolved"
 msgstr "Nộp gần đây"
 
+#: templates/problem/related_problems.html:3
+msgid "Recommended problems"
+msgstr "Bài tập gợi ý"
+
 #: templates/problem/search-form.html:2
 msgid "Problem search"
 msgstr "Tìm kiếm bài tập"
@@ -5767,6 +5764,12 @@ msgstr "Thông tin"
 msgid "Check all"
 msgstr "Chọn tất cả"
 
+#~ msgid "View comments"
+#~ msgstr "Xem bình luận"
+
+#~ msgid "Be the first to comment"
+#~ msgstr "Bình luận đầu tiên"
+
 #, fuzzy
 #~| msgid "Default"
 #~ msgid "default"
diff --git a/templates/actionbar/media-js.html b/templates/actionbar/media-js.html
index 78397e4..c3b7e0d 100644
--- a/templates/actionbar/media-js.html
+++ b/templates/actionbar/media-js.html
@@ -114,9 +114,7 @@
       });
 
       $('.actionbar-comment').on('click', function() {
-        if ($('#comment-announcement').length) {
-          $('#comment-announcement').click();
-        }
+        $('#comment-section').show();
         $('#write-comment').click();
       })
     });
diff --git a/templates/problem/problem.html b/templates/problem/problem.html
index 0dbcb66..97003a0 100644
--- a/templates/problem/problem.html
+++ b/templates/problem/problem.html
@@ -73,13 +73,9 @@
         $('#clarification_header_container').hide();
         window.scrollTo(0, document.body.scrollHeight);
       })
-      $('#comment-announcement').on('click', function() {
-        $('#comment-section').show();
-        $('#comment-announcement').hide();
-      })
 
       if (window.location.href.includes('#comment')) {
-        $('#comment-announcement').click();
+        $('#comment-section').show();
       }
 
       {% if not available_judges %}
@@ -380,17 +376,6 @@
       <br>
     {%- endif -%}
   {% endif %}
-  {% if not (contest_problem and contest_problem.contest.use_clarifications) %}
-    <div id="comment-announcement-container">
-      <div id="comment-announcement">
-        {% if has_comments %}
-          {{_('View comments')}} ({{comment_list.count()}})
-        {% else %}
-          {{_('Be the first to comment')}}
-        {% endif %}
-      </div>
-    </div>
-  {% endif %}
 {% endblock %}
 
 {% block comments %}
@@ -415,6 +400,7 @@
       {% include "comments/list.html" %}
     </div>
   {% endif %}
+  {% include "problem/related_problems.html" %}
   <iframe name="raw_problem" id="raw_problem"></iframe>
 {% endblock %}
 
diff --git a/templates/problem/related_problems.html b/templates/problem/related_problems.html
new file mode 100644
index 0000000..95ed05f
--- /dev/null
+++ b/templates/problem/related_problems.html
@@ -0,0 +1,19 @@
+{% if related_problems %}
+  <div class="content-description">
+    <h4>{{_('Recommended problems')}}:</h4>
+    <ul style="list-style-type: none; margin: 0.3em;">
+      {% for problem in related_problems %}
+        <li>
+          {% if problem.id in completed_problem_ids %}
+            <i class="solved-problem-color fa fa-check-circle"></i>
+          {% elif problem.id in attempted_problems %}
+            <i class="attempted-problem-color fa fa-minus-circle"></i>
+          {% else %}
+            <i class="unsolved-problem-color fa fa-minus-circle"></i>
+          {% endif %}
+          <a href="{{url('problem_detail', problem.code)}}">{{ problem.name }}</a>
+        </li>
+      {% endfor %}
+    </ul>
+  </div>
+{% endif %}
\ No newline at end of file