def buildDictionary(message):
    """
    counts the occurrence of every symbol in the message and store it in a python dictionary
      parameter:
        message: input message string
      return:
        python dictionary, key = symbol, value = occurrence
    """
    _dict = dict()
    for c in message:
        if c not in _dict.keys():
            _dict[c] = 1
        else:
            _dict[c] += 1
    return _dict