Problem Statement

You are given positive integers $N,M$. Consider a sequence of positive integers $A = (A_1, A_2, \ldots, A_N)$ that satisfies all of the following conditions.

• $A_1 = 1$
• For all $i\ (2 \le i \le N)$, $A_i \le M$
• For all $i\ (2 \le i \le N)$, $A_i = 2A_{i-1}$ or $A_i = 2A_{i-1} - 1$

It can be shown that under the constraints of this problem, a sequence $A$ satisfying the conditions always exists. Find a sequence $A$ satisfying the conditions whose sum of elements is maximum, and output that sum.

(Original idea: Cyanmond)

Input

$N$ $M$

• $1 \leq N, M \leq 10^9$
• All inputs are integers

Output

Output the answer on $1$ line.

Sample

4 5

11

2021 1

2021

314 159

625