#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define rrep(i,a,b) for(ll i=(ll)(a-1);i>=(ll)(b);i--)
#define MOD 998244353
//#define MOD 1e9+7
#define INF 1e16
//#define PI numbers::pi
//#define E numbers::e
template <typename T> bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template <typename T> bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}

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