codeforces#P1205B. Shortest Cycle

    ID: 30398 远端评测题 1000ms 256MiB 尝试: 1 已通过: 1 难度: 6 上传者: 标签>bitmasksbrute forcegraphsshortest paths*1900

Shortest Cycle

Description

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.

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

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

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

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.

Samples

4
3 6 28 9
4
5
5 12 9 16 48
3
4
1 2 4 8
-1

Note

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.