Write a recursive function using LISP that returns the Fibonacci number where the Fibonacci sequence is defined as

fib(0)=0, fib(1)=1 and fib(n) = fib(n-1) + fib(n-2) for n > 1.

examples:

n = 0 1 2 3 4 5 6 7 8 9 .....

fib(n) = 0 1 1 2 3 5 8 13 21 34 .....