input: 
  from typing import List
  
  def create_model_output(model_history: List[int]) -> str:
      """Given a list of integers representing the history of a model, return a string 
      in the format "X decisions were made. The most recent decision was Y."
      where X is the length of the history list and Y is the last element of the list.
      >>> create_model_output([1, 2, 3])
      '3 decisions were made. The most recent decision was 3.'
      >>> create_model_output([5, 10, 15, 20])
      '4 decisions were made. The most recent decision was 20.'
      """
  
output:     return f"{len(model_history)} decisions were made. The most recent decision was {model_history[-1]}."