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: import sys
  
  sys.setrecursionlimit(10**7)
  input = sys.stdin.readline
  
  N, X = map(int, input().split())
  
  numP_N = [0] * N
  numPB_N = [0] * N
  numP_N[0] = 3
  numPB_N[0] = 5
  for i in range(1, N):
      numP_N[i] = numP_N[i - 1] * 2 + 1
      numPB_N[i] = numPB_N[i - 1] * 2 + 3
  
  
  def rec(n, x):
      if n == 1:
          ans_1 = [0, 0, 1, 2, 3, 3]
          return ans_1[x]
  
      if x == numPB_N[n - 1]:
          return numP_N[n - 1]
  
      elif x > numPB_N[n - 2] + 2:
          return numP_N[n - 2] + 1 + rec(n - 1, x - numPB_N[n - 2] - 2)
  
      elif x == numPB_N[n - 2] + 2:
          return numP_N[n - 2] + 1
  
      elif x == numPB_N[n - 2] + 1:
          return numP_N[n - 2]
  
      elif x < numPB_N[n - 2] + 1:
          return rec(n - 1, x - 1)
  
  
  print(rec(N, X))
  
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."}]