Put 100 cups into several boxes, the number of each box is different from each other, and each box contains at least one cup, and how many boxes should be packed at most.
将100只杯子分别装入若干个盒子中，每盒装的只数互不相同，并且每盒至少装1只，最多要装入多少个盒子．
<result>13</result>