#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> PP;
//#define MOD 1000000007
#define MOD 998244353
#define INF 2305843009213693951
//#define INF 810114514
#define PI 3.141592653589
#define setdouble setprecision
#define REP(i,n) for(ll i=0;i<(n);++i)
#define OREP(i,n) for(ll i=1;i<=(n);++i)
#define RREP(i,n) for(ll i=(n)-1;i>=0;--i)
#define ALL(v) (v).begin(), (v).end()
#define GOODBYE do { cout << "-1" << endl; return 0; } while (false)
#define MM <<" "<<
#define Endl endl
#define debug true
#define debug2 false


int main(void){
    //cin.tie(nullptr);
    //ios::sync_with_stdio(false);
    
    ll H,A;
    cin >> H >> A;
    ll Ans = 0;
    ll h = H, num = 1;
    while(h>0){
        Ans += num;
        h = h/A;
        num *= 2;
    }
    cout << Ans << endl;

    return 0;
}