#include <bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
#define all(a) a.begin(),a.end()
typedef long long ll;
typedef pair<ll,int> P;
typedef vector<ll> vi;
constexpr ll inf=1ll<<61;
constexpr ll mod=998244353;
typedef modint998244353 mi;

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