In a spring outing, 31 people in class 3 of the third grade brought bread, 38 people brought drinks, 36 people brought fruit, and 34 people brought chocolate. There were 45 people in the whole class. People have all these four things.
在一次春游活动中，三年级3班有31人带了面包，有38人带了饮料，有36人带来水果，还有34人带了巧克力，全班共有45人，可以肯定至少有多少人这四样都带了．
<gadget id="calculator">45 * 3</gadget>
<output>135</output>

<gadget id="calculator">34 - 135</gadget>
<output>-101</output>

<gadget id="calculator">31 + 38 + 36 + (-101)</gadget>
<output>4</output>

<result>4</result>