#include <bits/stdc++.h>
using namespace std;

int main()
{
    int N, M;
    cin >> N >> M;
    long long ans = 0;
    for (int i = 0; i < N; ++i)
    {
        ans += M;
        M = (M + 1) / 2;
    }
    cout << ans << endl;
}