diff --git a/annotating_with_checks.py b/annotating_with_checks.py
index f56719f..86feafb 100644
--- a/annotating_with_checks.py
+++ b/annotating_with_checks.py
@@ -100,15 +100,21 @@ def natural_key(text):
 
 def process_student(args):
     """Thread worker: Processes one student."""
-    root_dir, student_id, labels = args
-    print(f"Generating Checkable PDF for: {student_id}")
+    root_dir, student_id, labels, overwrite = args
 
     output_dir = os.path.join(root_dir, "Bnot", f"Copie{student_id}")
+
     if os.path.exists(output_dir):
+        if not overwrite:
+            print(f"Skipping {student_id}: Output already exists.")
+            return
         shutil.rmtree(output_dir)
+
+    print(f"Generating Checkable PDF for: {student_id}")
     os.makedirs(output_dir)
 
     label_images = []
+    # ... (rest of the function remains exactly the same)
     all_checkboxes = []
     bnote_entries = [] # For bnote.json
 
@@ -178,17 +184,6 @@ def process_student(args):
     with open(os.path.join(output_dir, "checkboxes.json"), "w") as f:
         json.dump(final_json_map, f, indent=2)
 
-
-    # # Pour éviter du drift, avec img2pdf
-    # # Pb : Xournal can't add annotations
-    # temp_img_path = os.path.join(output_dir, "Reference.jpg")
-    # concat_img.save(temp_img_path, quality=90) # Save as standard image first
-    # with open(os.path.join(output_dir, "Concat.pdf"), "wb") as f:
-    #     f.write(img2pdf.convert(temp_img_path))
-
-
-    # Avec reportlab.pdfgen
-    # Au moins, le drift n'empire pas au fil de la copie
     temp_img_path = os.path.join(output_dir, "Reference.jpg") # Can't use png here
     concat_img.save(temp_img_path, quality=90)
 
@@ -198,21 +193,17 @@ def process_student(args):
     c.drawImage(temp_img_path, 0, 0, width=w, height=h)
     c.save()
 
-    # print("Debug : size", w, h)
-    # Ancien code, avec du drift
-    # concat_img.save(os.path.join(output_dir, "Concat.pdf"), "PDF", resolution=DPI)
-    # concat_img.save(os.path.join(output_dir, "Reference.png"))
-
-    # Try to fix the drift with 72 DPI, non essayé
-    # concat_img.save(os.path.join(output_dir, "Concat.pdf"), "PDF", resolution=72.0)
-    # concat_img.save(os.path.join(output_dir, "Reference.jpg"))
+import argparse # Added
 
 if __name__ == "__main__":
-    if len(sys.argv) < 2:
-        print("Usage: python annotating_with_checks.py <Dir> or <File>")
-        sys.exit(1)
+    parser = argparse.ArgumentParser(description="Generate annotated PDFs.")
+    parser.add_argument("input_path", help="Directory or specific file path")
+    parser.add_argument("--overwrite", action="store_true", help="Overwrite existing output files")
 
-    input_path = sys.argv[1]
+    args = parser.parse_args()
+
+    input_path = args.input_path
+    overwrite = args.overwrite # Capture flag
     target_id = None
 
     # Detect if input is a specific file
@@ -238,9 +229,7 @@ if __name__ == "__main__":
             print(f"Student ID {target_id} not found in directory scan.")
             results = {}
 
-    tasks = [(root_dir, sid, lbls) for sid, lbls in results.items()]
-
-    # print(tasks)
+    tasks = sorted([(root_dir, sid, lbls, overwrite) for sid, lbls in results.items()])
 
     with concurrent.futures.ThreadPoolExecutor(max_workers=2) as executor:
         results = executor.map(process_student, tasks)