系统随机生成一个不重复四位数。游戏者有5次猜出目标数的机会，每次游戏者输入后，系统会反馈信息。反馈信息的格式是：mBnA。这表示输入数与目标数有(m+n)个数字相同，有n个数字不仅数字本身相同而且位置也一致。

-The system generates a random number does not repeat four. The player has 5 times the opportunity to guess the target number, each time the player input, the system will feedback information. Feedback information in a format that is: mBnA. The representation of the input number and target number ( m+n ) number in the same, there are n number not only itself to the same location is also consistent and digital.