Define the function high_score that consumes a list of integers (representing scores in a game) and produces an integer representing the highest score in the list. Ignore scores less than 100, and stop processing values if you encounter -999. If the list is empty, return the value None instead. Also return None if no score of at least 100 comes before -999 (or before the end of the list). It is up to you to decompose this function (or not) however you want.