P22255 [CodeChef] GROUPASSGN
普及-
题目描述

Chef's professor is planning to give his class a group assignment. There are 2N students in the class, with distinct roll numbers ranging from 1 to 2N. Chef's roll number is X.

The professor decided to create N groups of 2 students each. The groups were created as follows: the first group consists of roll numbers 1 and 2N, the second group of roll numbers 2 and 2N - 1, and so on, with the final group consisting of roll numbers N and N+1.

Chef wonders who his partner will be. Can you help Chef by telling him the roll number of his partner?

------ Input Format ------

  • The first line of input will contain an integer T — the number of test cases. The description of T test cases follows.
  • The first and only line of each test case contains two integers N and X, denoting the number of groups that will be formed, and Chef's roll number.

------ Output Format ------

For each test case, output the roll number of the student that will be Chef's partner.

------ Constraints ------

$1 ≤ T ≤ 10^{3}$
$1 ≤ N ≤ 10^{8}$
$1 ≤ X ≤ 2N$

----- Sample Input 1 ------
3
2 2
3 1
3 4

----- Sample Output 1 ------
3
6
3
----- explanation 1 ------
Test case $1$: The groups will be $\{(1, 4), (2, 3)\}$. Chef's roll number is $2$, so his partner's roll number will be $3$.

Test case $2$: The groups will be $\{(1, 6), (2, 5), (3, 4)\}$. Chef's roll number is $1$, so his partner's roll number will be $6$.

Test case $3$: The groups will be $\{(1, 6), (2, 5), (3, 4)\}$. Chef's roll number is $4$, so his partner's roll number will be $3$.

输入格式

见题面

输出格式

见题面

样例输入
3 2 2 3 1 3 4
样例输出
3 6 3