output_description: Print the number of patties in the bottom-most X layers from the bottom of a
  level-N burger.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N X
attempt: memo = [[0, 1]]
  
  
  def f(n, b, p, k):
      if b + p == k:
          return [b, p]
      if n == 0:
          return [b, p + 1]
      newlst1 = [b + 1, p]
      if newlst1[0] + newlst1[1] == k:
          return newlst1
      newlst2 = [newlst1[0] + memo[n - 1][0], newlst1[1] + memo[n - 1][1]]
      if newlst2[0] + newlst2[1] == k:
          return newlst2
      if newlst2[0] + newlst2[1] > k:
          return f(n - 1, newlst1[0], newlst1[1], k)
      newlst3 = [newlst2[0], newlst2[1] + 1]
      if newlst3[0] + newlst3[1] == k:
          return newlst3
      newlst4 = [newlst3[0] + memo[n - 1][0], newlst3[1] + memo[n - 1][1]]
      if newlst4[0] + newlst4[1] == k:
          return newlst4
      if newlst4[0] + newlst4[1] > k:
          return f(n - 1, newlst3[0], newlst3[1], k)
      return [newlst4[0] + 1, newlst4[1]]
  
  
  N, K = map(int, input().split())
  for i in range(1, N):
      memo.append([2 * memo[i - 1][0] + 2, 2 * memo[i - 1][1] + 1])
  print(f(N, 0, 0, K)[1])
  
problem_description: Statement
  
  In some other world, today is Christmas.
  
  Mr. Takaha decides to make a multi-dimensional burger in his party. A _level-
  L burger_ (L is an integer greater than or equal to 0) is the following thing:
  
    * A level-0 burger is a patty.
    * A level-L burger (L \geq 1) is a bun, a level-(L-1) burger, a patty, another level-(L-1) burger and another bun, stacked vertically in this order from the bottom.
  
  For example, a level-1 burger and a level-2 burger look like `BPPPB` and
  `BBPPPBPBPPPBB` (rotated 90 degrees), where `B` and `P` stands for a bun and a
  patty.
  
  The burger Mr. Takaha will make is a level-N burger. Lunlun the Dachshund will
  eat X layers from the bottom of this burger (a layer is a patty or a bun). How
  many patties will she eat?
samples: [{"input": "2 7", "output": "4\n    \n\nThere are 4 patties in the bottom-most 7 layers of a level-2 burger\n(`BBPPPBPBPPPBB`).\n\n* * *"}, {"input": "1 1", "output": "0\n    \n\nThe bottom-most layer of a level-1 burger is a bun.\n\n* * *"}, {"input": "50 4321098765432109", "output": "2160549382716056\n    \n\nA level-50 burger is rather thick, to the extent that the number of its layers\ndoes not fit into a 32-bit integer."}]