[백준] 5032번 탄산 음료 문제! (bronze 2

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st=new StringTokenizer(br.readLine());
		int e=Integer.parseInt(st.nextToken());
		int f=Integer.parseInt(st.nextToken());
		int c=Integer.parseInt(st.nextToken());
		
		int bottle=e+f;
		int sum=0;
		while(true) {
			if(bottle/c==0) {
				break;
			}
			
			sum+=bottle/c;
			bottle=bottle/c+bottle%c;
		}
		bw.write(sum+"");
		bw.flush();
	
		
	}
}