There are 50 balls in a pocket, 10 of which are numbered 1, 2, 3, 4, and 5 each. At least how many small balls should be taken out at a time, and it can be guaranteed that there are at least 4 small balls with the same number.
一个口袋中有50个小球，编号为1，2，3，4，5的各有10个．一次至少要取出多少个小球，能保证其中至少有4个编号相同的小球．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<result>16</result>