There are 45 students in the second class of the sixth grade who have taken the graduation exam. Among them, 43 people have passed Chinese, 40 have passed mathematics, and 1 student has failed both Chinese and mathematics. How many people have passed both Chinese and mathematics?
六年级二班有45名同学参加毕业考试，其中语文及格的有43人，数学及格的有40人，有1人的语文和数字都没有及格，语文数学都及格的有多少人．
<gadget id="calculator">45 - 1</gadget>
<output>44</output>

<gadget id="calculator">40 - 44</gadget>
<output>-4</output>

<gadget id="calculator">43 + (-4)</gadget>
<output>39</output>

<result>39</result>