#include<bits/stdc++.h>
using namespace std;
//#include<atcoder/all>
//using namespace atcoder;
using ll = long long int;
using ull = unsigned long long int;
using ld = long double;
constexpr ll MAX = 2000000000000000000;
constexpr ld PI = 3.14159265358979;
constexpr ll MOD = 998244353;//2024948111;
ld dotorad(ld K){return PI * K / 180.0;}
ld radtodo(ld K){return K * 180.0 / PI;}
mt19937 mt;
void randinit(){srand((unsigned)time(NULL));mt = mt19937(rand());}
int main(){
    ll N,M;
    cin >> N >> M;
    if(N < 62 && M >= (1 << (N - 1))){
        cout << (1 << (N)) - 1 << endl;
        return 0;
    }
    ll ans = 0;
    vector<ll> A;
    while(M != 1){
        A.emplace_back(M);
        if(M & 1) M = (M + 1) / 2;
        else M /= 2;
    }
    A.emplace_back(1);
    reverse(A.begin(),A.end());
    ll a = (ll)A.size();
    for(ll i = 0;i < min(a,N);i++) ans += A[i];
    if(N <= a) cout << ans << endl;
    else cout << ans + (N - a) << endl;
}