#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001



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