1208: Diamond Collector

Bessie想让这些陈列架上的钻石保持相似的大小，所以她不会把两个大小相差K以上的钻石同时放在一个陈列架上（如果两颗钻石的大小差值为K，那么它们可以同时放在一个陈列架上）。现在给出K，请你帮Bessie确定她最多一共可以放多少颗钻石在这两个陈列架上。

Bessie the cow, always a fan of shiny objects, has taken up a hobby of mining diamonds in her spare time! She has collected  diamonds () of varying sizes, and she wants to arrange some of them in a pair of display cases in the barn.

Since Bessie wants the diamonds in each of the two cases to be relatively similar in size, she decides that she will not include two diamonds in the same case if their sizes differ by more than  (two diamonds can be displayed together in the same case if their sizes differ by exactly ). Given , please help Bessie determine the maximum number of diamonds she can display in both cases together.

第一行输入N和K（0<=K<=109）。接下去N行每行输入一个钻石的大小（正数且<= 109 ）。

The first line of the input file contains  and  ().

The next  lines each contain an integer giving the size of one of the

diamonds. All sizes will be positive and will not exceed .

输出一个数，表示Bessie最多可以放在两个陈列架上的钻石数量。

Output a single positive integer, telling the maximum number of diamonds that Bessie can showcase.

7 3
10
5
1
12
9
5
14

5