题库练习 Maximum Subsequence Value
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A13513 | Maximum Subsequence Value

时间限制1s
内存限制256MB
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题目描述

Ridhiman challenged Ashish to find the maximum valued subsequence of an array $a$ of size $n$ consisting of positive integers.

The value of a non-empty subsequence of $k$ elements of $a$ is defined as $\sum 2^i$ over all integers $i \ge 0$ such that at least $\max(1, k - 2)$ elements of the subsequence have the $i$ -th bit set in their binary representation (value $x$ has the $i$ -th bit set in its binary representation if $\lfloor \frac{x}{2^i} \rfloor \mod 2$ is equal to $1$ ).

Recall that $b$ is a subsequence of $a$ , if $b$ can be obtained by deleting some(possibly zero) elements from $a$ .

Help Ashish find the maximum value he can get by choosing some subsequence of $a$ .

输入格式

The first line of the input consists of a single integer $n$ $(1 \le n \le 500)$ — the size of $a$ .

The next line consists of $n$ space-separated integers — the elements of the array $(1 \le a_i \le 10^{18})$ .

输出格式

Print a single integer — the maximum value Ashish can get by choosing some subsequence of $a$ .

输入输出样例

输入 #1
3
2 1 3
输出 #1
3
输入 #2
3
3 1 4
输出 #2
7
输入 #3
1
1
输出 #3
1
输入 #4
4
7 7 1 1
输出 #4
7
C++ 编辑器
输入
输出