100 people answered five questions, 81 people answered the first question correctly, 91 people answered the second question correctly, 85 people answered the third question correctly, 79 people answered the fourth question correctly, 74 people answered the fifth question correctly, three questions or three questions correctly People with the above questions are regarded as passing, then, among the 100 people, at least how many people have passed.
100个人回答五道题，有81人答对第一题，91人答对第二题，85人答对第三题，79人答对第四题，74人答对第五题，答对三道题或三道题以上的人算及格，那么，在这100人中，至少有多少人及格．
<gadget id="calculator">100 * 5</gadget>
<output>500</output>

<gadget id="calculator">81 + 91 + 85 + 79 + 74</gadget>
<output>410</output>

<gadget id="calculator">500 - 410</gadget>
<output>90</output>

<gadget id="calculator">90 / 3</gadget>
<output>30</output>

<gadget id="calculator">100 - 30</gadget>
<output>70</output>

<result>70</result>