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

int main(){
	
	long long  h, a;
	cin >> h >> a;

	long long res = 0, now = 1;

	while(h > 0){
		res += now;
		h /= a;
		now *= 2;
	}
	
	cout << res << endl;


}