There is a bundle of wires, cut off half of the total length for the first time and 3 meters, cut off the remaining half for the second time and cut 4 meters, and cut off 15 meters for the third time, leaving 20 meters. How many meters is this wire?
有一捆电线，第一次剪下总长的一半多3米，第二次剪去剩下的一半少4米，第三次剪去15米，还剩20米．原来这根电线长多少米？
<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<gadget id="calculator">15 + 16</gadget>
<output>31</output>

<gadget id="calculator">31 * 2</gadget>
<output>62</output>

<gadget id="calculator">62 + 3</gadget>
<output>65</output>

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

<result>130</result>