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