Take half of the watermelons from the first pile and put them in the second pile, then take 35 and put them in the third pile, and take out the remaining half and put them in the fourth pile. In the end, there are 15 more in the first pile. How many watermelons were in the first pile?
从第一堆西瓜里拿出一半放到第二堆里，再拿35个放到第三堆里，又拿出剩下的一半放到第四堆里．最后第一堆还有15个．第一堆原有多少个西瓜？
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">30 + 35</gadget>
<output>65</output>

<gadget id="calculator">65 * 2</gadget>
<output>130</output>

<result>130</result>