input: Write a function to calculate the Fibonacci number at a given position. The function should recursively compute the Fibonacci sequence. If the given position is 0 then return 0, if it is 1 then return 1, otherwise return the sum of the previous two Fibonacci numbers.
  def fibonacci(n):
      if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return fibonacci(n-1) + fibonacci(n-2)
  
  n = 10
  print(fibonacci(n))
  
  assert fibonacci(0) == 0
  assert fibonacci(1) == 1
  assert fibonacci(10) == 55
  assert fibonacci(5) == 5
  assert fibonacci(7) == 13
output: def fibonacci(n):
      if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return fibonacci(n-1) + fibonacci(n-2)