#include<bits/stdc++.h>
using namespace std;
int cnt;
int n, k;
int yd;
int main() {
	cin >> n >> k;
	while(n != 0) {
		n--;
		yd++;
		if (yd == k) {
			cnt++;
			yd = 0;
		}
	}
	cnt += n;
	cout << cnt;
	return 0;
}

大佬们，我哪里错啦~~