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: def getItems(layerCount):
  	if layerCount == 0:
  		return 1
  	return 2*getItems(layerCount-1) + 3
  
  def getPats(layerCount):
  	return 2**(layerCount + 1) - 1
  
  def patEaten(layer, toEat):
  	pattyCount = 0
  
  	if layer == 1:
  		burger = "BPPPB"
  
  		for x in range(toEat):
  			if burger[x] == "P":
  				pattyCount += 1
  		return pattyCount
  		
  	elif layer == 0:
  		if toEat == 1:
  			return 1
  		else:
  			return 0
  	
  	else:
  		items = getItems(layer)
  		if toEat == items:
  			pattyCount += patEaten(layer, toEat)
        toEat = 0
  			return pattyCount
  		elif toEat < 2+getItems(layer-1):
  			if items + 1 == 2* toEat:
  				toEat-=2
  				return 1 + patEaten(layer - 1, toEat)
  			toEat -= 1
  			return patEaten(layer - 1, toEat)
  		else:
  			toEat -= (1+1+getItems(layer-1))
  			pattyCount += 1 + getPats(layer-1)
  			
  			return pattyCount + patEaten(layer-1, toEat)
  
  #i, j = [int(x) for x in input().split()]
  print(patEaten(2,13))
  #print(getItems(2))
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."}]