package main

import . "fmt"
import . "sort"

func main() {
	var n, m int
	Scan(&n,&m)
	
	x := Search(m+1, func(i int) bool {
		j := i
		c := 0
		for j > 1 {
			c++
			if j % 2 == 0 {
				j /= 2	
			} else {
				j = (j+1)/2
			}
		}
		return n - c < 0
	})
	x = min(m, max(1, x))
	s, c := 0, 0
	for x > 1 {
		s += x
		c++
		if x % 2 == 0 {
			x /= 2
		} else {
			x = (x+1)/2
		}
	}
	ans := s + (n-c)
	Println(ans)
}