devpy14

msg = bot.send_message(message.chat.id, "loading...")
...
bot.edit_message_text("result", chat_id=message.chat.id, message_id=msg.message_id)
bot.delete_message(message.chat.id, msg.message_id)

Set<String> uniqueStudents = new HashSet<>(map.values());

Set<String> set = map.values().stream()
                               .map(a -> a[0])
                               .collect(Collectors.toSet());