There are 60 wooden blocks of the same shape and size in the bag, and every 6 blocks are coded with the same number. How many blocks should be taken out at a time to ensure that at least three of them have the same number?
布袋中有60个形状、大小相同的木块，每6块编上相同的号码，一次至少取出几块，才能保证其中至少有三块的号码相同？
<gadget id="calculator">60 / 6</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<result>21</result>