You will be given a definition of a task first, then some input of the task.
This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Passage: The Prussian General Staff developed by Moltke proved to be extremely effective, in contrast to the traditional French school. This was in large part due to the fact that the Prussian General Staff was created to study previous Prussian operations and learn to avoid mistakes. The structure also greatly strengthened Moltke's ability to control large formations spread out over significant distances. The Chief of the General Staff, effectively the commander in chief of the Prussian army, was independent of the minister of war and answered only to the monarch. The French General Staffalong with those of every other European militarywas little better than a collection of assistants for the line commanders. This disorganization hampered the French commanders' ability to exercise control of their forces. Question: The General Staff developed by Moltke proved to be what?
Output:
extremely effective