There are 45 students in Class 1 of June. In the math test, 40 students passed the first time and 42 students passed the second time. How many students passed both times?
六1班有学生45人，数学测试，第一次有40人及格，第二次有42人及格，两次都及格的学生至少多少人．
<gadget id="calculator">42 - 45</gadget>
<output>-3</output>

<gadget id="calculator">40 + (-3)</gadget>
<output>37</output>

<result>37</result>