#include<bits/stdc++.h>
using namespace std;
#define ii int
#define ll long long
#define cc char
#define dd double
#define in cin
#define out cout
#define pp printf
#define bb bool
int main()
{
	ii a,k,sum=0,s=0;in>>a>>k;
	while(a){
		sum=a;
		s+=sum;
		sum/=k;
		sum=a-sum*k;
		a/=k;
		
		//TODO
	}cout<<s;
	return 0;
}