设计一个实现任意长的整数进行减法运算的演示程序。要求输入和输出每四位一组，组间用逗号隔开。如：1，0000，0000，0000，0000。-The design of a realization of arbitrary long integer subtraction calculations to carry out a demonstration program. Input and output requirements for each of four groups of groups separated by commas. Such as: 1,0000,0000,0000,0000.