func_code: def fibonacci(n):
      a, b = 0, 1
      for i in range(n):
          a, b = b, a + b
      return a
  
  
  def search(str, letter):
      i = 0
      while i < len(str):
          if str[i] == letter:
              return 'True'
          i = i + 1
      return 'False'