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: N, X = map(int, input().split())
  
  # (i)XがLバーガーの半分より上かどうか？を計算
  # (ii-i)上の場合: sumに下半分のパティの数を加算。下半分を切り捨てて、L-1バーガに対して、
  #        再度X = (X-(Lバーガーの半分の枚数))で(i)から計算
  # (ii-ii)下の場合: 上半分を切り捨てて、L-1バーガに対して再度X = (X-(Lバーガーの半分の枚数))で(i)から計算
  
  patty_num_map = {}
  size_map = {}
  patty_num_map[0] = 1
  size_map[0] = 1
  for i in range(1, 51):
      patty_num_map[i] = 1 + patty_num_map[i - 1] * 2
      size_map[i] = 3 + size_map[i - 1] * 2
  
  L = N
  patty_sum = 0
  L1_map = {}
  L1_map[0] = 0
  L1_map[1] = 0
  L1_map[2] = 1
  L1_map[3] = 2
  L1_map[4] = 3
  L1_map[5] = 3
  while True:
      half = size_map[L] // 2 + 1
      if L < 2:
          patty_sum += L1_map[X]
          break
      if X > half:
          patty_sum += patty_num_map[L - 1] + 1  # 真ん中のpattyの分
          # X -= half+1  # 一番上のバティの分
          X -= half
          L -= 1
      elif X < half:
          X -= 1  # 一番下のバンの分
          L -= 1
      else:  # ちょうど半分
          patty_sum += patty_num_map[L - 1] + 1
          break
  print(patty_sum)
  
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."}]