利用双向循环链表实现长整数的存储，每个结点含一个整形变量。任何整形变量的范围是 -(2^15 - 1)~ (2^15 - 1)。

输入和输出形式：按中国对于长整数的表示习惯，每四位一组，组间用逗号隔开。-use of a two-way cycle Chain achieve long integer storage, each node containing a plastic variables. Any shaping the scope of the variable - (2 ^ 15-1) ~ (2 ^ 15-1). Input and output forms : by China for the long integer said habits, a group of four, the group separated by a comma.