certain class subscribes for extracurricular reading materials. There are three kinds of publications A, B, and C. Each student subscribes at least one and at most three, but no matter how they order, there are at least 7 people who subscribe to the same situation. people?
某班征订课外读物，现有A、B、C三种刊物，每个学生至少订1种，最多订3种，但无论怎么订，都至少有7个人征订的情况相同，这个班至少有多少人？
<gadget id="calculator">6 * 7</gadget>
<output>42</output>

<gadget id="calculator">42 + 1</gadget>
<output>43</output>

<result>43</result>