"Ming solution Java" 10-2 in practice, each time you create an instance, identification Numbers are increasing n (n is positive), the n value is not specified the default is 1, but can get and modified, through methods such as, after created three instances, amend the n is 4, identification number assigned to the instance in order create 1,2,3,7,11,15...
Questions are modified, when the value of n identification number increasing accordingly? How to modify the following code?