class RecentCounter:
def __init__(self):
self.queue = deque()
def ping(self, t: int) -> int:
self.queue.append(t)
while self.queue and t - self.queue[0] > 3000:
self.queue.popleft()
return len(self.queue)
# Your RecentCounter object will be instantiated and called as such:
# obj = RecentCounter()
# param_1 = obj.ping(t)