3208. Sumsets

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

输入格式

Several $S$, each consisting of a line containing an integer $1 \leq n \leq 1000$ 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 $0$.

输出格式

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

样例

Input
5
2
3
5
7
12
5
2
16
64
256
1024
0

Output
12
no solution


1 人解决，2 人已尝试。

1 份提交通过，共有 2 份提交。

9.6 EMB 奖励。