input: 
  def build_dictionary(samples: List[str]) -> Dict[str, str]:
      """ Builds a dictionary from a list of string pairs separated by "->".
      Each string pair represents a key-value pair where the key is the part before "->"
      and the value is the part after "->".
      >>> build_dictionary(["apple->red", "banana->yellow", "cherry->red"])
      {'apple': 'red', 'banana': 'yellow', 'cherry': 'red'}
      """
  
output:     result = {}
      for sample in samples:
          key, value = sample.split("->")
          result[key] = value
      return result