def most_common_letter(input_string: str) -> str:
  counts = {}
  # count frequencies of each letter
  for letter in input_string:
    if letter in counts:
      counts[letter] += 1
    else:
      counts[letter] = 1
  
  # find the letter (key) with highest frequency
  most_common_letter = ""
  most_common_freq = -1
  for letter in counts:
    if counts[letter] > most_common_freq:
      most_common_freq = counts[letter]
      most_common_letter = letter
  return letter

def get_middle_value(input_list: list):
  num_elems = len(input_list)
  return input_list[num_elems // 2]

def get_word_counts(string: str) -> dict[str, int]:
  words = string.split()
  counts = {}
  for word in words:
    if word in counts:
      counts[word] += 1
    else:
      counts[word] = 1
  return counts