#include<bits/stdc++.h>

using namespace std;

using ll = long long;

int main(){
    ll N, X; cin >> N >> X;
    if (N <= 60 && (1ll << N) <= X) {
        cout << (1ll << (N + 1)) - 1 << endl;
    }
    else {
        ll ans = 0;
        while (X != 1) {
            ans += X;
            X = (X + 1) / 2;
            --N;
        }
        ans += N;
        cout << ans << endl;
    }
}