There is a column of numbers arranged according to the following rules: 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6 , 7, ... What is the 200th number in this column.
有一列数，按照下列规律排列：1，2，2，3，3，3，4，4，4，4，5，5，5，5，5，6，6，6，6，6，6，7，…这列数的第200个数是多少．
<result>20</result>