//
//  main.cpp
//  AndeyLess
//
//  Created by Kadir Kadyrov on 08.07.2020.
//  Copyright © 2020 Kadir Kadyrov. All rights reserved.
//

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

int main() {
    int a, b;
    cin >> a >> b;
    int curr = a, ans = 0, currB = 0;

    while(curr > 0) {
        ans += curr;
        currB += curr;
        curr = currB / b;
        currB %= b;
    }

    cout << ans << endl;
}