#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
#include<string>
using namespace std;


int main()
{
    long long n, l, t;
    cin >> n >> l;
    t = (n+l-1)/l;
    cout << pow(2, t) -1 << endl;
}