local mfl, mce = math.floor, math.ceil
local n, m = io.read("*n", "*n")
local function solve(x)
  local cnt = 1
  while 1 < x do
    x = mce(x / 2)
    cnt = cnt + 1
  end
  return cnt <= n
end
local function solve2(x)
  local cnt = 0
  local ret = 0
  while 1 < x do
    ret = ret + x
    x = mce(x / 2)
    cnt = cnt + 1
  end
  return ret + (n - cnt)
end
if solve(m) then
  print(solve2(m))
  os.exit()
end
local min, max = 1, m
while 1 < max - min do
  local mid = mfl((min + max) / 2)
  if solve(mid) then
    max = mid
  else
    min = mid
  end
end
print(solve2(max))