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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll h, a;
    cin >> h >> a;
    function<ll(ll)> rec = [&](ll v) -> ll {
        if(v <= 0) return 0;
        return 2 * rec(v / a) + 1;
    };
    cout << rec(h) << '\n';
}