Recursion Tracing Exercise: Mystery Return

Consider the following function: int mystery(int a, int b) { if (b == 1) return a; else return a + mystery(a, b - 1); } What is the return of calling mystery(2,0)?
(Either write a number, or write "infinite recursion".)

infinite recursion

Initially b = 0, and the recursive function keeps on decrementing b. Do you think that it will ever reach the base case?