#include <bits/stdc++.h>   using namespace std;   int main() {     long long h, n;     cin >> h >> n;     long long l = 1, r = (1LL << h), ret = 0, cur = 0, dir = 0;     while (cur < h) {       long long size = (1LL << (h - cur)), mid = (l + r) / 2;       if (dir == 0) {         if (n <= mid)           ++ret, r = mid, dir = 1;         else           ret += size, l = mid + 1;       } else {         if (n <= mid)           ret += size, r = mid;         else           ++ret, l = mid + 1, dir = 0;       }       ++cur;     }     cout << ret << endl;   }   