#include<bits/stdc++.h>
using namespace std;
int main(){
	int yd=0,cy=0,a,b;
	cin>>a>>b;
	yd+=a;
	cy+=a;
	while(yd>=b){
		cy+=yd/b;
		yd=yd/b;
	}
	cout<<cy;
return 0;
}