func_code: def fibonacci(n):
      i = 0
      num = 1
      num1 = 1
      num2 = 1
      while i < n:
          if n == 0:
              return 0
          elif n == 1:
              return 1
          num = num2 + num1
          num1 = num2
          num2 = num
          i = i + 1
      if n != 0 and n != 1:
          return num