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