UVa 10346 - Peter's Smokes

// UVa 10346 - Peter's Smokes
#include <iostream>
using namespace std;

int main() {
	int n, k;
	while (cin >> n >> k) {
		int left = n;
		int butts = 0;
		int smoked = 0;
		while (left) {
			smoked += left;
			butts += left;
			left = butts / k;
			butts = butts % k;
		}
		cout << smoked << endl;
	}
	return 0;
}