#include<iostream>
using namespace std;
int main() {
	int n,k,m;
	cin>>n>>k;
	m=n;
	m+=n/k;
	n=n%k+n/k;
	while(n>k){
		m+=n/k;
		n%=k+n/k;
	}
	cout<<m;
	return 0;
}