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

#define rep(i, a, b) for (int i = (int)(a); (i) < (int)(b); (i)++)
#define rrep(i, a, b) for (int i = (int)(b) - 1; (i) >= (int)(a); (i)--)
#define all(v) v.begin(), v.end()

typedef long long ll;
template <class T> using V = vector<T>;
template <class T> using VV = vector<V<T>>;


int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    constexpr char endl = '\n';

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