There are 586 people in Li Village, and there are 123 mobile phones. If you want a mobile phone for every 2 people. How many phones are left?
李村有586人，现有手机123部．如果要每2人一部手机．还差多少部手机？
<gadget id="calculator">586 / 2</gadget>
<output>293</output>

<gadget id="calculator">293 - 123</gadget>
<output>170</output>

<result>170</result>