#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < n; i++)
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)

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