Class 1 holds a shooting competition. It is stipulated that each person shoots 5 balls, one point for each shot, and no score for a missed shot. In order to ensure that 3 people have the same score, at least how many people must participate in this competition.
六1班举行投篮比赛，规定每人投5球，投进一球的一分，投不进不得分，为了保证有3人的得分相同，至少要有多少人参加这项比赛．
<gadget id="calculator">2 * 6</gadget>
<output>12</output>

<gadget id="calculator">12 + 1</gadget>
<output>13</output>

<result>13</result>