Now there are 64 ping-pong balls and 18 ping-pong boxes. At most 6 ping-pong balls can be placed in each box. At least several ping-pong boxes have the same number of ping-pong balls.
现在有64个乒乓球，18个乒乓球盒，每个盒子里最多可以放6只乒乓球，至少有几个乒乓球盒子里的乒乓球数目相同．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<result>4</result>