$8 \cdot 19$ The blackboard has the integer 1000 written on it, and there are 1000 matches on the table. Two people, A and B, play a game: A starts and they take turns. The person whose turn it is can take no more than 5 matches from the pile, or they can put no more than 5 matches back into the pile (but at the start, neither has any matches, and when putting matches back, they can only use matches they have previously taken), and they write down the current number of matches in the pile on the blackboard. If a person writes down a number that is already on the blackboard, they lose. Assuming both players use the correct strategy, who will win?