#include <iostream>
#include <iomanip>
#include <vector>
#include <utility>
#include <map>
#include <algorithm>
#include <queue>
#include <cmath>
#include <numeric>
#include <set>

using namespace std;
struct aaa{aaa(){cin.tie(nullptr); ios::sync_with_stdio(false); cout<<fixed<<setprecision(20);};}aaa;
template <class T>ostream &operator<<(ostream &o,const vector<T>&v){o<<"{";for(int i=0;i<(int)v.size();i++)o<<(i>0?", ":"")<<v[i];o<<"}";return o;}
#define debug(v) {cerr<<"\033[1;36m[debug]\033[m "<<#v<<" : "<<v<<endl;}

using int64 = long long;

#include <iostream>
#include <vector>

using namespace std;

const int64 MOD = 998244353;
long long pow(long long a, long long n, long long p) {
    long long res = 1;
    while(n!=0) {
        if (n%2) {
            res *= a;
            res %= p;
        }
        a *= a;
        a %= p;
        n >>= 1;
    }
    return res % p;
}

int main() {
    int64 n,l;
    cin >> n >> l;
    n = (n+l-1)/l;
    int64 ans = pow(2,n) - 1;
    cout << ans << endl;
}