loves to build snowmen. But his favorite type has to be arithmetic snowmen. An arithmetic snowman consists of 3 snowballs whose sizes, when arranged in a non-decreasing order, form an arithmetic sequence. For example, can make an arithmetic snowman out of snowballs of sizes 1, 3, and 5.
The size of an arithmetic snowman is the sum of the sizes of the snowballs that it's made of. ~N~ snowballs of varying sizes, find the largest arithmetic snowman he can make!has made
Subtask 1 [50%]
~3 \le N \le 100~
~1 \le size \le 100~
Subtask 2 [50%]
~3 \le N \le 3000~
~1 \le size \le 10^5~
The first line of input will contain ~N~, the number of snowballs.
The second line of input will contain ~N~ space-separated integers, the sizes of the snowballs.
One integer, the size of the largest arithmetic snowmancan build. It is guaranteed that he can build at least one.
7 4 2 8 10 14 3 7
Explanation for Sample Output
will use the snowballs of sizes 2, 8, and 14 to make the snowman.