Problem Statement
You are given two positive integers $N$ and $K$. A positive integer $X$ is called compatible with $N$ if it satisfies the following condition:
- The bitwise XOR of
$X$and$N$is equal to the remainder when$X$is divided by$N$.
Determine whether there exist at least $K$ such integers $X$ that are compatible with $N$. If they do exist, find the $K$-th smallest such integer.
You are given $T$ test cases; solve each of them.
About XOR The bitwise XOR of nonnegative integers $A$ and $B$, denoted $A\ \mathrm{XOR}\ B$, is defined as follows: In the binary representation of $A\ \mathrm{XOR}\ B$, the digit in the $2^k$ place (for $k \geq 0$) is $1$ if and only if exactly one of $A$ and $B$ has a $1$ in the $2^k$ place in its binary representation. Otherwise, it is $0$. For example, $3\ \mathrm{XOR}\ 5 = 6$ (in binary: $011\ \mathrm{XOR}\ 101 = 110$).
Constraints
$1 \le T \le 2\times 10^5$$1 \le N,K \le 10^9$- All input values are integers.
Input
The input is given from Standard Input in the following format:
T
\text{case}_1
\text{case}_2
\vdots
\text{case}_T
Here, $\text{case}_i$ denotes the $i$-th test case.
Each test case is given in the following format:
N K
Output
For each test case, if there exist at least $K$ positive integers that are compatible with $N$, print the $K$-th smallest such integer. Otherwise, print -1.
样例
4
2 1
2 2
1 7
20250126 191
2
3
-1
20381694
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