## Description:

Lindsay is a shopaholic. Whenever there isa discount of the kind where you can buy

three items and only pay for two, she goes

completely mad and feels a need to buy all

items in the store. You have given up on

curing her for this disease, but try to limit

its effect on her wallet.

You have realized that the stores coming with these offers are quite selective when it

comes to which items you get for free; it is always the cheapest ones. As an example,

when your friend comes to the counter with seven items, costing 400, 350, 300, 250, 200,

150, and 100 dollars, she will have to pay 1500 dollars. In this case she got a discount

of 250 dollars. You realize that if she goes to the counter three times, she might get a

bigger discount. E.g. if she goes with the items that costs 400, 300 and 250, she will get a

discount of 250 the first round. The next round she brings the item that costs 150 giving

no extra discount, but the third round she takes the last items that costs 350, 200 and

100 giving a discount of an additional 100 dollars, adding up to a total discount of 350.

Your job is to find the maximum discount Lindsay can get.

## Input:

The first line of input gives the number of test scenarios, 1 *≤ **t **≤ *20. Each scenario

consists of two lines of input. The first gives the number of items Lindsay is buying,

1 *≤ **n **≤ *20000. The next line gives the prices of these items, 1 *≤ **p**i **≤ *20000.

## Output:

For each scenario, output one line giving the maximum discount Lindsay can get by

selectively choosing which items she brings to the counter at the same time.

## Sample Input:

1

6

400 100 200 350 300 250

## Sample Output:

400

## Note:

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本题由旧版NOJ导入，来源：Nordic Collegiate Programming Contest 2007