diff --git a/dlibrary/dlibrary.py b/dlibrary/dlibrary.py
index bb669e9..deaf3ee 100755
--- a/dlibrary/dlibrary.py
+++ b/dlibrary/dlibrary.py
@@ -25,19 +25,7 @@ FANZA_ID_REGEX = re.compile('^d_[0-9]+$')
 FAKKU_ID_REGEX = re.compile('.*_FAKKU$')
 
 TEXTLESS_REGEX = re.compile('(台詞|セリフ)(な|無)し|notext|textless')
-EPILOGUE_REGEX = re.compile('after|後日談')
-ALT_VERSIONS = [
-    '褐色',
-    '日焼け',
-    'pink',
-    '金髪',
-    '白肌',
-    'うつろ目',
-    'dark skin',
-    'ラバー',
-    'ゾンビ肌',
-    'マスク',
-]
+ALT_VERSIONS = ['褐色', '日焼け', 'pink']
 
 IMAGE_FILE_EXTENSIONS = ['.png', '.jpg', '.jpeg', '.gif', '.tiff']
 
@@ -213,11 +201,8 @@ def complete_prefix_number_ordering(entries):
 
     entries_by_version = {}
     for entry in entries:
-        version_code = 0
-        for (i, version) in enumerate(ALT_VERSIONS):
-            if version in entry.name:
-                version_code |= (1 << i)
-        entries_by_version.setdefault(version_code, []).append(entry)
+        version = next(ver for ver in (ALT_VERSIONS + ['']) if ver in entry.name)
+        entries_by_version.setdefault(version, []).append(entry)
 
     numberings_by_version = {ver: unique_hierarchical_prefix_numbering(entries_by_version[ver]) for ver in entries_by_version}
 
@@ -226,7 +211,6 @@ def complete_prefix_number_ordering(entries):
         if numbering is None:
             return None
         unified_indices |= set(numbering.keys())
-    unified_indices.discard(None)
     unified_indices = list(unified_indices)
     unified_indices.sort()
 
@@ -240,8 +224,6 @@ def complete_prefix_number_ordering(entries):
                         return None
                     break
 
-    unified_indices.append(None)
-
     versions = list(numberings_by_version.keys())
     versions.sort()
 
@@ -262,34 +244,26 @@ def complete_prefix_number_ordering(entries):
     return result
 
 def unique_hierarchical_prefix_numbering(entries, start_point=0):
-    if len(entries) == 1 and not NUMBER_REGEX.search(entries[0].name):
-        return {None: entries}
-
-    longest_entry = max(entries, key=lambda e: len(e.name))
-    matches = reversed(list(NUMBER_REGEX.finditer(longest_entry.name)))
+    matches = reversed(list(NUMBER_REGEX.finditer(entries[0].name)))
     for m in matches:
         pos = m.start()
         if pos < start_point:
             return None
-        prefix = longest_entry.name[:pos]
-        if all(e.name.startswith(prefix) or prefix.startswith(e.stem) for e in entries):
+        prefix = entries[0].name[:pos]
+        if all(e.name.startswith(prefix) for e in entries):
             numbering = {}
             for e in entries:
-                if pos >= len(e.stem):
-                    i = 0
-                else:
-                    n = NUMBER_REGEX.match(e.name[pos:])
-                    if n is None:
-                        return None
-                    i = int(n.group())
+                n = NUMBER_REGEX.match(e.name[pos:])
+                if n is None:
+                    return None
+                i = int(n.group())
                 numbering.setdefault((i,), []).append(e)
 
             indices = list(numbering.keys())
             for idx in indices:
                 if len(numbering[idx]) > 1:
                     ents_idx = numbering.pop(idx)
-                    longest = max(ents_idx, key=lambda e: len(e.name))
-                    next_layer_start = pos + NUMBER_REGEX.match(longest.name[pos:]).end()
+                    next_layer_start = pos + NUMBER_REGEX.match(ents_idx[0].name[pos:]).end()
                     sub_numbering = unique_hierarchical_prefix_numbering(ents_idx, start_point=next_layer_start) or alphabetic_numbering(ents_idx, next_layer_start)
                     if not sub_numbering:
                         return None
@@ -371,26 +345,6 @@ def collate(args):
     collation_staging_area.rmdir()
     con.close()
 
-def collate_regex_later(srcs, dest, regex, start_index):
-    matching = []
-    nonmatching = []
-    for src in srcs:
-        if regex.search(src.name):
-            matching.append(src)
-        else:
-            nonmatching.append(src)
-
-    if not (matching and nonmatching):
-        return False
-
-    nonmatching_pages = collate_from_paths(nonmatching, dest, start_index)
-    if nonmatching_pages is None:
-        return None
-    matching_pages = collate_from_paths(matching, dest, start_index+nonmatching_pages)
-    if matching_pages is None:
-        return None
-    return nonmatching_pages + matching_pages
-
 def collate_from_paths(srcs, dest, start_index):
     if len(srcs) == 1 and srcs[0].is_dir():
         return collate_from_paths(ls_ignore(srcs[0]), dest, start_index)
@@ -402,13 +356,21 @@ def collate_from_paths(srcs, dest, start_index):
     if len(srcs) == 0:
         return 0
 
-    textless_split = collate_regex_later(srcs, dest, TEXTLESS_REGEX, start_index)
-    if textless_split != False:
-        return textless_split
-
-    epilogue_split = collate_regex_later(srcs, dest, EPILOGUE_REGEX, start_index)
-    if epilogue_split != False:
-        return epilogue_split
+    with_text = []
+    textless = []
+    for src in srcs:
+        if TEXTLESS_REGEX.search(src.name):
+            textless.append(src)
+        else:
+            with_text.append(src)
+    if with_text and textless:
+        text_pages = collate_from_paths(with_text, dest, start_index)
+        if text_pages is None:
+            return None
+        textless_pages = collate_from_paths(textless, dest, start_index+text_pages)
+        if textless_pages is None:
+            return None
+        return text_pages + textless_pages
 
     if all(src.is_file() and src.suffix.lower() in IMAGE_FILE_EXTENSIONS for src in srcs):
         ordering = complete_prefix_number_ordering(srcs)