#include <bits/stdc++.h>
#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
#include<string>
using ll = long long;
using namespace std;

int main(){
    ll h, a, sq = 1, ans = 0;
    cin >> h >> a;
    while (h){
        h /= a;
        ans += sq;
        sq *= 2;
    }
    cout << ans << endl;
}