def parse_query(query):
  query_dictionary = {}
  split_query = query[1:].split('&')
  for item in split_query:
    item_key, item_val = item.split('=')[0], item.split('=')[1]
    if item_key not in query_dictionary:
      query_dictionary[item_key] = item_val
    elif item_key in query_dictionary:
      prev_contents = query_dictionary[item_key]
      query_dictionary[item_key] = [prev_contents]
      query_dictionary[item_key].append(item_val)
  return query_dictionary