If a task is done alone, A needs to complete it in 1 day beyond the specified time, and B needs to complete it in 6 days beyond the specified time. If two people work together for 4 days, and B will do the rest, it will be completed in 1 day beyond the specified time, so how many days is the specified time?
一项工作，如果单独做，甲要超过规定时间1天完成，乙要超过规定时间6天完成．如果二人合作4天，余下的由乙来做，则超过规定时间1天完成，那么规定时间是多少天．
<gadget id="calculator">4 * 6</gadget>
<output>24</output>

<gadget id="calculator">1 - 6</gadget>
<output>-5</output>

<gadget id="calculator">24 + (-5)</gadget>
<output>19</output>

<gadget id="calculator">1 - 4 - 1 - 1 - 1</gadget>
<output>-6</output>

<gadget id="calculator">1 + 6 + (-6)</gadget>
<output>1</output>

<gadget id="calculator">19 / 1</gadget>
<output>19</output>

<result>19</result>