#include<iostream>
using namespace std;
int main()
{
	int n,m=0,a,s=0,b;
	cin>>n>>a;
	while(m+n>a||m>0)
		{
			s+=n;
			n=0;
			m+=n;
			b=m/a;
			n+=b;
			b*=a;
			m-=b;
		}
	cout<<s;
	return 0;
}