UVA - 573 - The Snail

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


public class Main {

    public static void main(String[] args) throws IOException {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        StringBuffer sb = new StringBuffer("");
            while (true) {
               String[] str=br.readLine().split(" ");
               if(str[0].equals("0"))
                   break;
               double h,u,d,f;
               h=Integer.parseInt(str[0]);
               u=Integer.parseInt(str[1]);
               d=Integer.parseInt(str[2]);
               f=Integer.parseInt(str[3]);
               double start=0,fact=u*f/100.0;
               int counter=0;
               boolean suc=false;
               while(true){
                   ++counter;
                   if(counter>1)
                       u-=fact;
                   if(u>=0)
                       start+=u;
                   if(start>h){
                       suc=true;
                       break;
                   }
                   start-=d;
                   if(start<0)
                       break;
               }
               if(suc)
                    sb.append("success on day ").append(counter).append("\n");
               else
                   sb.append("failure on day ").append(counter).append("\n");
            }
            System.out.print(sb);
    }

}