Three people, A, B, and C, participated in an intelligence test. A answered the most questions correctly. The sum of the questions answered by any two of them was 39, 50, and 47 respectively. So how many questions does A get right?
甲、乙、丙三人参加了一次智力测验，甲答对题目最多，他们中任意两个人答对的问题之和分别是39、50、47．那么甲答对多少道问题．
<gadget id="calculator">50 + 39 + 47</gadget>
<output>136</output>

<gadget id="calculator">136 / 2</gadget>
<output>68</output>

<gadget id="calculator">68 - 39</gadget>
<output>29</output>

<result>29</result>