175. Encoding

time limit per test: 0.75 sec / memory limit per test: 32768 KB

Let phi(W) is the result of encoding for algorithm: 1. If the length of W is 1 then phi(W) is W; 2. Let coded word is W = w1w2…wN and K = N / 2 (rounded down); 3. phi(W) = phi( \(w_Nw_{N-1}...w_{K+1}\)) + phi( \(w_Kw_{K-1}...w_1\)). For example, phi(‘Ok’) = ‘kO’, phi(‘abcd’) = ‘cdab’. Your task is to find position of letter \(w_q\) in encoded word phi(W).

Input

Given integers N, q (1 <= N <= 10^9; 1<= q <= N), where N is the length of word W.

Output

Write position of letter wq in encoded word phi(W).

Example(s)

Sample Input	Sample Output
9 4	8