There are a total of 44 three-wheeled agricultural vehicles, four-wheeled minibuses and six-wheeled trucks in a certain parking lot, and there are 171 wheels of each kind. It is known that one four-wheeled minibus is twice as small as the six-wheeled truck. Then this How many three-wheeled agricultural vehicles are there in the parking lot?
某停车场中有三轮农用车、四轮中巴车和六轮大卡车共44辆，各种轮子共有171个，已知四轮中巴车比六轮大卡车的2倍少一辆，那么这个停车场中共有多少辆三轮农用车？
<gadget id="calculator">3 * 44</gadget>
<output>132</output>

<gadget id="calculator">171 - 132 - 3</gadget>
<output>36</output>

<gadget id="calculator">4 + 36</gadget>
<output>40</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">8 - 9</gadget>
<output>-1</output>

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

<gadget id="calculator">40 / 5</gadget>
<output>8</output>

<gadget id="calculator">3 * 8</gadget>
<output>24</output>

<gadget id="calculator">44 - 24</gadget>
<output>20</output>

<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<result>21</result>