B"At first, let's define function f(x) as follows: begin{matrix} f(x) & = & <= ft { begin{matrix} frac{x}{2} & mbox{if } x text{ is even} x - 1 & mbox{otherwise } end{matrix} right. end{matrix} We can see that if we choose some value v and will apply function f to it, then apply f to f(v) , and so on, we'll eventually get 1 . Let's write down all values we get in this process in a list and denote this list as path(v) . For example, path(1) = [1] , path(15) = [15, 14, 7, 6, 3, 2, 1] , path(32) = [32, 16, 8, 4, 2, 1] . Let's write all lists path(x) for every x from 1 to n . The question is next: what is the maximum value y such that y is contained in at least k different lists path(x) ? Formally speaking, you need to find maximum y such that <= ft| { x ~|~ 1 <= x <= n, y in path(x) } right| ge k . The first line contains two integers n and k ( 1 <= k <= n <= 10^{18} ). Print the only integer -- the maximum value that is contained in at least k paths. In the first example, the answer is 5 , since 5 occurs in path(5) , path(10) and path(11) . In the second example, the answer is 4 , since 4 occurs in path(4) , path(5) , path(8) , path(9) , path(10) and path(11) . In the third example n = k , so the answer is 1 , since 1 is the only number occuring in all paths for integers from 1 to 20 . "...