Codeforces Round 580 (Div. 1)
B
Shortest Cycle
Codeforces
1900
原题
← AC →
翻译中…

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.

翻译中…

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

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Input

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

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

翻译中…

Output

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

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Note

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

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

翻译中…

The graph has no cycles in the third example.

翻译中…

样例

Input #1
4
3 6 28 9
Output #1
4
InputCopy OutputCopy
Input #2
5
5 12 9 16 48
Output #2
3
InputCopy OutputCopy
Input #3
4
1 2 4 8
Output #3
-1
InputCopy OutputCopy
题目信息
题号
1205B
时间限制
1 s
内存限制
256 MB
标签
位运算
暴力
图论
最短路

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