#include <iostream>
using namespace std;
typedef long long ll;

int main()
{
    int n, m;
	cin >> n >> m;
    int k = 1;
    for(int i = 0; i < n - 1; i++){
        k *= 2;
        if(k > m){
            k = m;
            break;
        }
    }
    ll ans = 0;
    while(n && k > 1){
        ans += k;
        k = (k + 1) / 2;
        n--;
    }
    ans += n;
    cout << ans << endl;
}