A. Equilateral

You are given N rods with sizes S1,S2,S3 ... SN. You can connect two rods with sizes Si and Sj to turn them into one rod with size Si+Sj.

You need to create the largest equilateral triangle possible out of the rods. So connect the rods in a way that you have 3 rods with exactly the same size.

You do not need to utilise all the rods.

   equilateral triangle


Each input will contain several test cases.

The first line of each test case will contain one number N indicating the amount of rods. The next line will contain N numbers (S1 ... SN) separated by spaces. The last line of the input will contain a 0.

Looking into the inputs you can verify that 1 <= Si <= 100 and 4 <= N <= 100.


For each test case print one line with the size of the side of the biggest equilateral triangle that can be built out of the given rods. If no equilateral triangle can be built then print 0.

Example input

1 1 1 1 1
1 2 3 4
2 4 4 9 3 7 6 2

Example output