Fix the combination length calculation

corrector.py

@@ -212,7 +212,7 @@ def reed_solomon(points, data_length, last_error_index, prime_number):
     Returns:
         str: The corrected message.
     """
-    combination_length = data_length - len(points[:last_error_index])
+    combination_length = data_length - len(points[last_error_index + 1:])
 
     # Parse each combination of points possible (exclude the correct points)
     for x in itertools.combinations(points[: last_error_index + 1], combination_length):