There are four classes in the fourth grade of Hope Primary School, among which there are 81 students in Class One and Class Two, 83 students in Class Two and Class Three, and 86 students in Class Three and Class Four. Class One has 2 more students than Class Four. How many people are there in Class One? people?
希望小学四年级有四个班，其中一班和二班共有81人，二班和三班共有83人，三班和四班共有86人，一班比四班多2人，一班有多少人？
<gadget id="calculator">2 - 81</gadget>
<output>-79</output>

<gadget id="calculator">86 + (-79)</gadget>
<output>7</output>

<gadget id="calculator">83 - 7</gadget>
<output>76</output>

<gadget id="calculator">76 / 2</gadget>
<output>38</output>

<gadget id="calculator">81 - 38</gadget>
<output>43</output>

<result>43</result>