There is no solution to this problem, and the counterexample is as follows: Suppose a 1= 100, and a2~a99 are all zero. If the condition A= 100 is satisfied, then S (100) =121,and A = (9900+121)1.

Title browsing: browse by content title and read the content of interest in detail.

Classified reading: it is easier to form a knowledge system by systematically studying and reading a topic in the application.

Search function: You can use the search function to quickly locate what you vaguely remember for your own reference.

Function introduction:

Sequential reading: You can read all the contents of the application in turn, which is most effective when you first start using it.

Collecting and reading: collecting the contents that are difficult and easy to forget in learning can focus on overcoming the obstacles in learning, surprise review and break them one by one.