5. Recursion: Consider the following program.

 public class RecursionMystery { 

 public static int mystery(int n) { 

 if( n <= 0 ) return 0; 

 else if( n == 1 ) return 1; 

 else return n + mystery( n - 2 ) ; 

 } public static void main(String[] args) { 

System.out.println( mystery(1) ); //----1

System.out.println( mystery(-6) ); //-------2

System.out.println( mystery(3) ); //-------3

 } }//end of class 

A) How many base cases are there in the recursive function mystery above? What are they?

B) Trace the execution of the function call in statement 3 above?

C)

What is the output of the above program?