/**
 * Title:
 * Description:
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author Burton Rosenberg
 * @version 1.0
 *
 * 10 Sept 2003 
 *
 */

import java.io.* ;
import java.util.* ;

public class ReadIntegers {

  String prompt ;
  String huhString ;
  StringTokenizer st = new StringTokenizer("") ;
  BufferedReader br ;

  public ReadIntegers(String prompt, String huhString) {
     this.prompt = prompt ;
     this.huhString = huhString ;
     br = new BufferedReader(new InputStreamReader(System.in)) ;
  }

  int nextInteger() throws ReadIntegersException
  {
     do {
       try {
         while ( !st.hasMoreTokens() )
         {
               if ( prompt!=null ) System.out.print(prompt);
               String s = br.readLine() ;
               if ( s==null ) throw new ReadIntegersException() ;
               st = new StringTokenizer(s) ;
               // empty lines terminate. remove the following
               // line if this behavior is not wanted
               if ( !st.hasMoreTokens() ) throw new ReadIntegersException() ;
         }
         return Integer.parseInt(st.nextToken()) ;
       }
       // catch blocks
         catch ( NumberFormatException nfs )
         {
            // if huhString != null, complain about bad input
            // before retrying, else be silent (non-interactive mode).
            if ( huhString!=null ) System.out.println(huhString) ;
         }
         catch  ( IOException ioe ) { } ;
     } while (true) ;
  }

}