Class Chats:
    def __init__(self):
    self.vk_chats = []
    self.tg_chats = []
    
    def add_vk_chat(self, vk_chat_id):
    self.vk_chats.append(vk_chat_id)

    def add_tg_chat(self, tg_chat_id):
        self.tg_chats.append(tg_chat_id)

    def remove_vk_chat(self, vk_chat_id):
        self.vk_chats.remove(vk_chat_id)

    def remove_tg_chat(self, tg_chat_id):
        self.tg_chats.remove(tg_chat_id)

    def contains(self, chat_id):
        return chat_id in self.tg_chats or chat_id in self.vk_chats

    def __len__(self):
        return len(self.tg_chats) + len(self.vk_chats)