Buggy python submission (verdict: Runtime Error):
inp = input().split()
layer = int(inp[0])
length = int(inp[1])
lengths = [5]
ps = [3]
for i in range(49):
  lengths.append(lengths[i]*2+3)
  ps.append(ps[i]*2+1)
print(stack(layer, length))

def stack(layer, length):
  if layer==1:
    return "BPPPB"[:length].count("P")
  else:
    if length==(lengths[layers-1]+1)/2:
      return ps[layers-1]+1
    elif length==(lengths[layers-1]+1)/2:
      return stack(layers-1, length-1)
    else:
      return ps[layers-1]+1+stack(layers-1, length-(lengths[layers-2]+2)

Fixed submission:
def stack(layer, length):
  if layer==1:
    return "BPPPB"[:length].count("P")
  else:
    if length==(lengths[layer-1]+1)/2:
      return ps[layer-2]+1
    elif length<(lengths[layer-1]+1)/2:
      return stack(layer-1, length-1)
    else:
      return ps[layer-2]+1+stack(layer-1, length-lengths[layer-2]-2)
    
inp = input().split()
layer = int(inp[0])
length = int(inp[1])
lengths = [5]
ps = [3]
for i in range(49):
  lengths.append(lengths[i]*2+3)
  ps.append(ps[i]*2+1)
print(stack(layer, length))

Buggy python submission (verdict: Time Limit Exceeded):
nx = input()
nx = nx.split()
n = int(nx[0])
x = int(nx[1])
burgers = [None] * 51
burgers[0] = "P"
burgers[1] = "BPPPB"
burgers[2] = "BBPPPBPBPPPBB"
i = 3
while i<=50:
  burgers[i] = "B" + burgers[i-1] + "P" + burgers[i-1] + "B"
  i+=1
result = burgers[n][:x-1]
print(result.count("P"))

Fixed submission:
def stack(layer, length):
  if layer==1:
    return "BPPPB"[:length].count("P")
  else:
    if length==(lengths[layer-1]+1)/2:
      return ps[layer-2]+1
    elif length<(lengths[layer-1]+1)/2:
      return stack(layer-1, length-1)
    else:
      return ps[layer-2]+1+stack(layer-1, length-lengths[layer-2]-2)
    
inp = input().split()
layer = int(inp[0])
length = int(inp[1])
lengths = [5]
ps = [3]
for i in range(49):
  lengths.append(lengths[i]*2+3)
  ps.append(ps[i]*2+1)
print(stack(layer, length))

Buggy python submission (verdict: Runtime Error):
#include <bits/stdc++.h>
using namespace std;

int main() {
  long long int n, x, i;
  string result;
  cin >> n >> x;
  vector<string> burgers[51];
  burgers[0] = "P";
  burgers[1] = "BPPPB";
  burgers[2] = "BBPPPBPBPPPBB";
  i = 3;
  while (i<=50) {
    burgers[i] = "B" + burgers[i-1] + "P" + burgers[i-1] + "B";
    i+=1;
  }
  result = burgers[n][:x-1];
  cout << result;
  return 0;
}

/*
nx = input()
nx = nx.split()
n = int(nx[0])
x = int(nx[1])
burgers = [None] * 51
burgers[0] = "P"
burgers[1] = "BPPPB"
burgers[2] = "BBPPPBPBPPPBB"
i = 3
while i<=50:
  burgers[i] = "B" + burgers[i-1] + "P" + burgers[i-1] + "B"
  i+=1
result = burgers[n][:x-1]
print(result.count("P"))
*/

Fixed submission:
def stack(layer, length):
  if layer==1:
    return "BPPPB"[:length].count("P")
  else:
    if length==(lengths[layer-1]+1)/2:
      return ps[layer-2]+1
    elif length<(lengths[layer-1]+1)/2:
      return stack(layer-1, length-1)
    else:
      return ps[layer-2]+1+stack(layer-1, length-lengths[layer-2]-2)
    
inp = input().split()
layer = int(inp[0])
length = int(inp[1])
lengths = [5]
ps = [3]
for i in range(49):
  lengths.append(lengths[i]*2+3)
  ps.append(ps[i]*2+1)
print(stack(layer, length))

Buggy python submission (verdict: Time Limit Exceeded):
nx = input()
nx = nx.split()
n = int(nx[0])
x = int(nx[1])
burgers = [None] * 51
burgers[0] = "P"
burgers[1] = "BPPPB"
burgers[2] = "BBPPPBPBPPPBB"
i = 3
while i<=50:
  burgers[i] = "B" + burgers[i-1] + "P" + burgers[i-1] + "B"
  i+=1
result = burgers[n][:x-1]
print(result.count("P"))

Fixed submission:
def stack(layer, length):
  if layer==1:
    return "BPPPB"[:length].count("P")
  else:
    if length==(lengths[layer-1]+1)/2:
      return ps[layer-2]+1
    elif length<(lengths[layer-1]+1)/2:
      return stack(layer-1, length-1)
    else:
      return ps[layer-2]+1+stack(layer-1, length-lengths[layer-2]-2)
    
inp = input().split()
layer = int(inp[0])
length = int(inp[1])
lengths = [5]
ps = [3]
for i in range(49):
  lengths.append(lengths[i]*2+3)
  ps.append(ps[i]*2+1)
print(stack(layer, length))