#include <iostream>
using namespace std;
int main()
{
	int n,k,k1 = 0,a = 0,sum = 0;//k1用来处存烟蒂，sum共吸了多少 ，a不定 
	cin >> n >> k;
	k1 += n;
	sum += n;
	while (k1 > k){
		a = n % k;
		n += a;
		sum += a;
		k1 += a;
		k1 %= k;
		a = 0; 
	}
	cout << sum;
	return 0;
}