text: def fibonacci(nth, prev=1, curr=1):
      '''
      Return the nth number in the Fibonacci sequence.
  
      The Fibonacci sequence starts with 1 1 2 3 5 8.
      For instance, for nth 5 it returns 8.
      '''
      if nth == 0:
          return curr
  
      if nth == 1:
          return curr
  
      prev, curr = curr, prev + curr
      nth -= 1
      return fibonacci(nth, prev, curr)
  