#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;

int main(){
    ull h,a;
    cin >> h >> a;
    ull check=a;
    ull t=2;
    ull su = 1;
    while(check<=h){
        check*=a;
        su += t;
        t *= 2;
    }
    cout << su << endl;
}