说明：  这是一个支持多位数运算（可以达到几百位的长整数）的数类，名字叫Long，它是从long类发展过来的，但比原来的long类功能多。Long类可以和原有的double，long等等数据类型混合运算
(This is a multi-digit support operations (which may reach hundreds of long integers) to a number of named Long, it is long from over the type of development, but more than the original multi-functional long. Long classes can be double the original, long data types, etc. Operational mixed)