Using the following recursive Fibonacci algorithm:
 

    def fib(n):
       if n==0:
          return 0
       elif n==1
          return 1
       return (fib(n-1)+fib(n-2))


If I inputted the number 5 to find fib(5), I know this will output 5 but how do I examine the complexity of this algorithm? How do I calculate the steps involved?