For a bundle of rope, half of the total length is used for the first time and less than 7 meters, and the remaining half is used for the second time, more than 4 meters, leaving 10 meters. How long is the bundle of rope?
一捆绳子，第一次用去全长的一半少7米，第二次用去余下的一半多4米，还剩10米．这捆绳子原来长多少米？
<gadget id="calculator">4 + 10</gadget>
<output>14</output>

<gadget id="calculator">14 * 2</gadget>
<output>28</output>

<gadget id="calculator">28 - 7</gadget>
<output>21</output>

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<result>42</result>