There are 50 students in a class, 26 of them got full marks in one test, and 21 got full marks in the second test. If there are 17 students who did not get perfect marks on both tests, how many students got perfect marks on both tests?
某班有50名学生，在一次测验中有26人满分，在第二次测验中有21人满分．如果两次测验都没得过满分的学生有17人，那么两次测验都得满分的有多少人？
<gadget id="calculator">50 - 17</gadget>
<output>33</output>

<gadget id="calculator">21 - 33</gadget>
<output>-12</output>

<gadget id="calculator">26 + (-12)</gadget>
<output>14</output>

<result>14</result>