Maximum value
##### Submissions: 1624   Accuracy: 26.48%   Difficulty: Easy   Marks: 2

Find the maximum value of arr[j] – arr[i] + arr[l] – arr[k], such that i < j < k < l
Example:
Let us say our array is {4, 8, 9, 2, 20} Then the maximum such value is 23 (9 – 4 + 20 – 2)

Note: If n<4 then print -1.

Input:

The first line of input contains a single integer T denoting the number of test cases. Then T test cases follow. Each test case consist of two lines. The first line of each test case consists of an integer N, where N is the size of array.The second line of each test case contains N space separated integers denoting array elements.

Output:
Corresponding to each test case, in a new line, print the maximum value of arr[j] – arr[i] + arr[l] – arr[k].

Constraints:
1 ≤ T ≤ 100
1 ≤ N ≤ 500
1 ≤ A[i] ≤ 1000

Example:

Input
1
5
4 8 9 2 20

Output
23

#### ** For More Input/Output Examples Use 'Expected Output' option **

Author: rajatjha

If you have purchased any course from GeeksforGeeks then please ask your doubt on course discussion forum. You will get quick replies from GFG Moderators there.