说明：  一个猜单词的小游戏wordZ。该程序将从一个字典中随机地选择一个单词，并用’－’字符告诉用户该单词有几个字母。用户每次输入一个字母后，程序判断该字母是否在该单词中，如果有则显示该单词中所有该字母，否则提示没有猜中。用户可以最多有8次猜测的机会（重复输入的字母不计入在内。）。如果用户在最大的猜测机会内猜中了该单词，则该次游戏用户胜利，否则用户失败。
(A guess word game wordZ. The program will randomly choose a dictionary, a word and use '-' character to tell the user there are several letters of the word. After each time a user enter a letter, the program to determine whether the letter of the word, if there is displayed in all the letters in the word, otherwise there is no guess prompted. Users can have up to eight times the chance to guess (to re-type the letters are not included in included.). If the user within the maximum opportunity to guess guessed the word, then the second game players win, or the user fails.)