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

int main() {
  ll H, A;
  cin >> H >> A;
  ll ans = 0, cnt = 1;
  while(H > 0) {
    ans += cnt;
    H /= A;
    cnt *= 2;
  }
  cout << ans << endl;
}