#include <bits/stdc++.h>
using namespace std;
long long int mod = 1e9 + 7;
long long int dx[] = {0, 0, 1, -1};
long long int dy[] = {1, -1, 0, 0};
long long int m = 0, n, res = 0, k, h;
string s2, ch = "", s, s1 = "";
vector<pair<string, long long int> > vm;
vector<pair<pair<long long int, long long int>, long long int> > vvv;
vector<pair<long long int, long long int> > vv, vv2;
vector<long long int> v[200005], cur;
void solve(long long int lev, char c, long long int n) {
  res++;
  if (!lev || !n) return;
  long long int mid = (1LL << lev) / 2;
  if (c == 'L') {
    if (n > mid) {
      long long int sm = 0;
      for (long long int j = 0; j <= (lev - 1); j++) sm += (1LL << j);
      n -= mid;
      res += sm;
      solve(lev - 1, 'L', n);
    } else {
      solve(lev - 1, 'R', n);
    }
  } else {
    if (n <= mid) {
      long long int sm = 0;
      for (long long int j = 0; j <= (lev - 1); j++) sm += (1LL << j);
      res += sm;
      solve(lev - 1, 'R', n);
    } else {
      n -= mid;
      solve(lev - 1, 'L', n);
    }
  }
}
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  long long int i = 0, x = 0, z = 0, y = 0, j = 0, q, mx = 0, idx = 0, ok = 0,
                l = 0, r = 0, negatif = 0, positif = 0, l1, r1, t, g = 0;
  set<long long int>::iterator it;
  cin >> h >> n;
  if (!h) return cout << "0", 0;
  res = 0;
  solve(h, 'L', n);
  res--;
  cout << res;
  return 0;
}
