#include <bits/stdc++.h>
using namespace std;

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