#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define rep(i, a, n) for (int i = (int)(a); i < (int)(n); i++)
#define rrep(i, n, a) for (int i = (int)(n); i >= (int)(a); i--)

void solve(){
    ll h,a; cin >> h >> a;
    ll ans = 0;
    ll j = 1;
    while(h>0){
        h = h/a;
        ans += j;
        j *= 2;
    }
    cout << ans;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    solve();

    return 0;
}