Problem B - Sticks
After inspecting the problem set TA give to HT, he feels a little tired and decides to go for a walk. As a naughty boy, HT picks up n sticks during his walk, each with a length ai. HT wonders if he can choose three from the n sticks such that the three sticks can form a triangle with the maximum possible perimeter (周長). HT is a busy professor, so he wants you to help him decide the maximum possible perimeter of the triangles that could be formed.
The first line contains an integer T, representing the number of testcases.
Each testcase contains two lines :
The first line contains an integer n, representing the number of sticks HT picks.
The second line contains n integer ai, representing the length of each sticks.
It is guaranteed that :
If you can't pass testcase #9 & #10 immediately, try to solve another two problems first.
For each testcase, please output a line contains one integer represents the length of the triangle with the maximum possible perimeter. If the sticks can't form a triangle, please output -1.