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5332: Subarray Cuts

内存限制：256 MB 时间限制：2 S
题面：传统 评测方式：文本比较 上传者：
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题目描述

E2. Subarray Cuts
time limit per test
2 seconds
memory limit per test
512 megabytes
input
standard input
output
standard output
You are given an array of length n and a number k. Let's pick k non-overlapping non-empty subarrays of the initial array. Let si be the sum of the i-th subarray in order from left to right. Compute the maximum value of the following expression:
|s1-s2|+|s2-s3|+...+|sk-1-sk| Here subarray is a contiguous part of an array.
Input
The first line of input contains two integers n and k. The second line contains n integers − the elements of the array. The absolute values of elements do not exceed 104.
The problem consists of two subproblems. The subproblems have different constraints on the input. You will get some score for the correct submission of the subproblem. The description of the subproblems follows.
  • In subproblem E1 (9 points), constraints 2≤n≤400, 2≤k≤min(n,50) will hold.
  • In subproblem E2 (12 points), constraints 2≤n≤30000, 2≤k≤min(n,200) will hold.
Output
Output a single integer − the maximum possible value.
Examples
Input 
5 3
5 2 4 3 1
Output 
12
Input 
4 2
7 4 3 7
Output 
8
Note
Consider the first sample test. The optimal solution is obtained if the first subarray contains the first element only, the second subarray spans the next three elements and the last subarray contains the last element only. The sums of these subarrays are 5, 9 and 1, correspondingly.
Consider the second sample test. In the optimal solution, the first subarray consists of the first two elements and the second subarray consists of the third element only. Note that the last element does not belong to any subarray in this solution.

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