Get Max Increments

Rearrange all the integers in any order to maximize the number of adjacent positions with a[i]<a[i+1]. This is not the longest increasing subsequence.

输入格式

The first line contains n; the second line contains the scores. 2≤n≤200000, 1≤score≤200000.

输出格式

Output a single integer, the answer.

样例 1

输入：

3
2 1 3

输出：

2

样例 2

输入：

4
2 1 1 2

输出：

2

样例 3

输入：

2
5 5

输出：

0

样例说明

The answers are 2, 2 and 0; in the second example the arrangement 1,2,1,2 rises at positions 0 and 2, and the source's 0 and 1 is wrong.