title: How many characters can be input into the "prompt" for GPT-2
body: <p>I'm using the OpenAI GPT-2 model from <a href="https://github.com/openai/gpt-2" rel="nofollow noreferrer">github</a></p>
  <p>I think that the top_k parameter dictates how many tokens are sampled. Is this also the parameter that dictates how large of a prompt can be given?</p>
  <p>If top_k = 40, how large can the prompt be?</p>