#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    ll N,M; cin >> N >> M;
    auto f = [&](ll N, ll M) {
        ll p2 = 1;
        for(int i = 0; i < N; i++) {
            if(p2 >= M) return true;
            p2 *= 2;
        }
        return false;
    };
    if(f(N, M)) {
        ll ans = 0;
        ll m = M;
        ll cnt = 0;
        while(m != 1) {
            ans += m;
            if(m % 2 == 0) {
                m /= 2;
            } else {
                m = (m + 1) / 2;
            }
            cnt++;
        }
        cout << ans  + 1 * (N - cnt) << endl;
    } else {
        ll ans = 0;
        ll a = 1;
        for(int i = 0; i < N; i++) {
            ans += a;
            a *= 2;
        }
        cout << ans << endl;
    }
}