P4337 [CF1205B] Shortest Cycle
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题目描述

You are given $n$ integer numbers $a_1, a_2, \dots, a_n$. Consider graph on $n$ nodes, in which nodes $i$, $j$ ($i\neq j$) are connected if and only if, $a_i$ AND $a_j\neq 0$, where AND denotes the bitwise AND operation.

Find the length of the shortest cycle in this graph or determine that it doesn't have cycles at all.

Input

The first line contains one integer $n$ $(1 \le n \le 10^5)$ — number of numbers.

The second line contains $n$ integer numbers $a_1, a_2, \dots, a_n$ ($0 \le a_i \le 10^{18}$).

Output

If the graph doesn't have any cycles, output $-1$. Else output the length of the shortest cycle.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
4 3 6 28 9
样例输出
4
提示

In the first example, the shortest cycle is $(9, 3, 6, 28)$.

In the second example, the shortest cycle is $(5, 12, 9)$.

The graph has no cycles in the third example.