Fix indexing problem

app.py

@@ -135,7 +135,7 @@ class TsgDocFinder:
             return self.indexer[original_id]
         
         for doc in self.indexer:
-            if original_id.startswith(doc):
+            if doc.startswith(original_id):
                 return self.indexer[doc]
         
         # Parse the document ID