There are 10 multiple-choice questions in a mathematics competition. The scoring standard is: 10 points for the basics, 3 points for a correct answer, 1 point deducted for a wrong answer, and 0 points for no answer. It is known that at least 4 of the students who took the test scored the same. So, at least how many students take the test.
一次数学竞赛有10道选择题，评分标准是：基础分10分，答对一题得3分，打错一题倒扣1分，不答得0分．已知参加考试的学生中，至少有4人得分相同．那么，参加考试的学生至少有多少人．
<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">30 + 10</gadget>
<output>40</output>

<gadget id="calculator">40 + 1</gadget>
<output>41</output>

<gadget id="calculator">41 - 3</gadget>
<output>38</output>

<gadget id="calculator">38 * 3</gadget>
<output>114</output>

<gadget id="calculator">114 + 1</gadget>
<output>115</output>

<result>115</result>