text: '''Exeptions and controll flow'''
  import sys
  from math import log
  
  def convert(s):
      x = -1
      try:
          return int(s)
      except (ValueError, TypeError) as e:
          print('Conversion error: {}'\
                .format(str(e)),
                file=sys.stderr)
          raise
  
  
  def string_log(s):
      v = convert(s)
      return log(v)
  
  