Write a program named Mystery.java. In the Mystery class, you write a recursive method named "mystery" and then call it from the main() method to print the return result with the following two test cases a) mystery(3, 2, 6) b) mystery(2, 2, 6) For n>=0, the mystery function defines as follows: mystery(n, a, b)=1 when n=0 (base condition) mystery(n, a, b) = mystery(n-1, a-1, b-2) + mystery(n-2, a-2, b-3), when n>0