diff --git a/_config.yml b/_config.yml
index 213bb2f..c285938 100644
--- a/_config.yml
+++ b/_config.yml
@@ -28,8 +28,14 @@ exclude: [PATAdvanced/, PATBasic/, Gemfile, Gemfile.lock, source]
 
 # collections
 collections:
-  articles:
+  Advanced:
     output: true
-    permalink: /:path:output_ext
+    permalink: /:collection/:path:output_ext
+  Basic:
+    output: true
+    permalink: /:collection/:path:output_ext
+  Top:
+    output: true
+    permalink: /:collection/:path:output_ext
 
 # vim:tabstop=2:softtabstop=2:shiftwidth=2
diff --git a/source/build.py b/source/build.py
index 4c5e860..bc35d18 100755
--- a/source/build.py
+++ b/source/build.py
@@ -104,15 +104,14 @@ class FileBuilder:
         """
         write everything to a final markdown file
         """
-        filename = "{}/{}{:04}.md".format(config.md_dir, self.c, self.i)
+        tag = config.tag[self.c]
         category = config.category[self.c]
 
+        filename = os.path.join(config.md_dir, "_" + category, "{:04}.md".format(self.i))
         title, problem_div = self.read_html()
         code, code_url = self.read_code()
         date, expl = self.read_expl()
 
-        tag = config.tag[self.c]
-
         print("Building {}".format(filename))
 
         with open(filename, 'w') as f:
diff --git a/source/config.py b/source/config.py
index 60581a9..283a280 100644
--- a/source/config.py
+++ b/source/config.py
@@ -1,6 +1,6 @@
 #! /usr/bin/env python3
 
-md_dir = "../_articles"               # The dir of final generated markdown file
+md_dir = "../"               # The dir of final generated markdown file
 html_dir = "html"           # The dir of html file from patest.cn
 analysis_dir = "analysis"   # The dir of md files of only analysis text
 code_dir = {                # Children folders of code_dir