UVA Problem ID 10346 (Peter's Smokes)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;


public class Main {
	public static void main (String args[]) throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		String input;
		StringBuilder sb=new StringBuilder(1000);
		
		while((input=br.readLine())!=null)
		{
			String s[]=input.split(" +");
			int n=Integer.parseInt(s[0]);
			int k=Integer.parseInt(s[1]);
			int total_cigarettes=n;
			int butts=n;
			while(butts>=k)
			{
				total_cigarettes+=butts/k;
				butts=butts/k+butts%k;
			}
			sb.append(total_cigarettes+"\n");
		}
		System.out.print(sb);
	}
}