Sumsets（http://noi.openjudge.cn/ch0305/1551/）

描述

Given S, a set of integers, find the largest d such that a + b + c = d where a, b, c, and d are distinct elements of S.

输入

Several S, each consisting of a line containing an integer 1 <= n <= 1000 indicating the number of elements in S, followed by the elements of S, one per line. Each element of S is a distinct integer between -536870912 and +536870911 inclusive. The last line of input contains 0.

输出

For each S, a single line containing d, or a single line containing "no solution".

描述

给出S，一组整数，找出最大的d，使a+b+c=d，a、b、c、d是S中的不同元素。

输入

若干S，每个S由一行组成，该行包括一个整数1<=n<=1000，表示S中的元素个数，随后是S中的所有元素，每行一个。S中的每个元素都是介于-536870912到+536870911之间的整数。输入的最后一行为0。

输出

对于每组S，一个包含d的单行，或者一个包含”no solution”的单行。