A stationery store bought 400 soft cover exercise books, sold 110 on the first day and 190 on the second day, how many are left?
文具店买来400个软皮练习本，第一天卖出110个，第二天卖出190个，还剩多少个？
<gadget id="calculator">400 - 110 - 190</gadget>
<output>100</output>

<result>100</result>