Being a nonconformist, Volodya is displeased with the current state of things, particularly with the order of natural numbers $($natural number is positive integer number$).$ He is determined to rearrange them. But there are too many natural numbers, so Volodya decided to start with the first n$.$ He writes down the following sequence of numbers: firstly all odd integers from $1$ to n $($in ascending order$),$ then all even integers from $1$ to n $($also in ascending order$).$ Help our hero to find out which number will stand at the position number k$.$

Input

The only line of input contains integers n and k $(1<=$k$<=$n$<=1012).$

Please, do not use the $\%$lld specifier to read or write $64-$bit integers in C$++.$ It is preferred to use the cin, cout streams or the $\%$I$64$d specifier.

Output

Print the number that will stand at the position number k after Volodya's manipulations.