#include <iostream>
#include <stdio.h>
using namespace std; int main()
{
//freopen("acm.acm","r",stdin);
int n;
int k;
int sum;
int mod;
int tem;
while(cin>>n>>k)
{
sum = ;
while(n >= k)
{
mod = n % k;
tem = n / k;
sum += n - mod;
n = mod + tem;
}
sum += mod + tem;
cout<<sum<<endl; }
}