Codeforces Round 1035 (Div. 2)
C
A Good Problem
Codeforces
1300
原题
← BD →
翻译中…

You are given four positive integers $n, l, r, k$. You need to find the lexicographically smallest$^{\text{∗}}$ array $a$ of length $n$, consisting of integers, such that:

翻译中…
  • For every $1 \leq i \leq n$, $l \leq a_i \leq r$.
  • $a_1 \, \& \, a_2 \, \& \, \ldots \, \& \, a_n = a_1 \oplus a_2 \oplus \ldots \oplus a_n$, where $\&$ denotes the bitwise AND operation and $\oplus$ denotes the bitwise XOR operation.
翻译中…

If no such array exists, output $-1$. Otherwise, since the entire array might be too large to output, output $a_k$ only.

翻译中…

$^{\text{∗}}$An array $a$ is lexicographically smaller than an array $b$ if and only if one of the following holds: $a$ is a prefix of $b$, but $a \ne b$; or in the first position where $a$ and $b$ differ, the array $a$ has a smaller element than the corresponding element in $b$.

翻译中…

Input

翻译中…

Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

翻译中…

Each test case contains four positive integers $n,l,r,k$ ($1 \le k \le n \le 10^{18}$, $1 \le l \le r \le 10^{18}$).

翻译中…

Output

翻译中…

For each test case, output $a_k$ or $-1$ if no array meets the conditions.

翻译中…

Note

翻译中…

In the first test case, the array $a = [4]$. It can be proven that there is no array that meets the above requirements and has a smaller lexicographic order.

翻译中…

In the second test case, the array $a= [1,1,1]$. It can be proven that there is no array that meets the above requirements and has a smaller lexicographic order.

翻译中…

In the third test case and the fourth test case, the array $a = [6,6,8,8]$. It can be proven that there is no array that meets the above requirements and has a smaller lexicographic order.

翻译中…

In the fifth test case and the sixth test case, it can be proven that there is no array that meets the above requirements.

翻译中…

样例

Input #1
9
1 4 4 1
3 1 3 3
4 6 9 2
4 6 9 3
4 6 7 4
2 5 5 1
2 3 6 2
999999999999999999 1000000000000000000 1000000000000000000 999999999999999999
1000000000000000000 1 999999999999999999 1000000000000000000
Output #1
4
1
6
8
-1
-1
-1
1000000000000000000
2
InputCopy OutputCopy
题目信息
题号
2119C
时间限制
2 s
内存限制
256 MB
标签
位运算
构造
数学

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。