RAZLIKA

문제

Mirko's newest math homework assignment is a very difficult one! Given a sequence, V, of N integers, remove exactly K of them from the sequence. Let M be the largest difference of any two remaining numbers in the sequence, and m the smallest such difference. Select the K integers to be removed from V in such a way that the sum M + m is the smallest possible. Mirko isn't very good at math, so he has asked you to help him! 

입력

The first line of input contains two positive integers, N (3 ≤ N ≤ 1 000 000) and K (1 ≤ K ≤ N - 2). 

The second line of input contains N space-separated positive integers – the sequence V (-5 000 000 ≤ V_i ≤ 5 000 000). 

출력

The first and only line of output must contain the smallest possible sum M + m. 

 

5 2
-3 -2 3 8 6

7

6 2
-5 8 10 1 13 -1

13

6 3
10 2 8 17 2 17

6