title: Telegram, getting file_id for existing sticker
body: <p>I'm writing a Telegram bot and I want it to send a sticker.</p>
  
  <p>It is said <a href="https://core.telegram.org/bots/api#sendsticker">here</a>, that to send a sticker that already exists on Telegram servers we can simply pass <em>file_id</em>. The thing is, I have absolutely no idea how to obtain <em>file_id</em> of any sticker. E.g. how do I send any sticker from Greater Minds pack? I suppose, this pack is on Telegram servers since they include it in every app.</p>