CF1194A.Remove a Progression
普及/提高-
通过率:0%
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题目描述
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).
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?
输入格式
The first line contains one integer T ( 1≤T≤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≤x<n≤109 ) — 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.
输出格式
Print T integers (one per query) — the values of the x -th number after performing the algorithm for the corresponding queries.
输入输出样例
输入#1
3 3 1 4 2 69 6
输出#1
2 4 12