Remove a Progression

2000ms

262144K

Description:

You have a list of numbers from $$$1$$$ to $$$n$$$ written from left to right on the blackboard.

You perform an algorithm consisting of several steps (steps are $$$1$$$-indexed). On the $$$i$$$-th step you wipe the $$$i$$$-th number (considering only remaining numbers). You wipe the whole number (not one digit).

$\text{[math]}$

When there are less than $$$i$$$ numbers remaining, you stop your algorithm.

Now you wonder: what is the value of the $$$x$$$-th remaining number after the algorithm is stopped?

Input:

The first line contains one integer $$$T$$$ ($$$1 \le T \le 100$$$) — the number of queries. The next $$$T$$$ lines contain queries — one per line. All queries are independent.

Each line contains two space-separated integers $$$n$$$ and $$$x$$$ ($$$1 \le x < n \le 10^{9}$$$) — the length of the list and the position we wonder about. It's guaranteed that after the algorithm ends, the list will still contain at least $$$x$$$ numbers.

Output:

Print $$$T$$$ integers (one per query) — the values of the $$$x$$$-th number after performing the algorithm for the corresponding queries.

Sample Input:

Sample Output:

2
4
12

Informação

Provedor Codeforces

Código CF1194A