bins.cpp

#include <iostream>
#include <vector>
#include <cassert>

using namespace std;

const int MAXD = 20;
vector<bool> tree(1<<20, true);

int main(){
    int depth, num;
    while(cin>> depth>> num){
        for(int i = 0; i< (1<<depth); i++){
            tree[i] = false;
        }
        int cur = 1;
        int secondlast = 1<<(depth-1);
        for(int i = 0; i< num; i++ ){
            cur = 1;
            while(cur < secondlast){
                assert(cur < tree.size());
                if(tree[cur]){
                    tree[cur] = false;
                    cur = cur*2 + 1 ;
                }else{
                    tree[cur] = true;
                    cur = cur*2;
                }
            }
        }
        cout << cur << endl;
    }
}