import javax.swing.*;

public class BadArgument
{
    public static void main( String [] args )
    {
        while ( true )
        {
            String answer = JOptionPane.showInputDialog( "Escriba un entero" );
            int intAnswer = Integer.parseInt( answer );
            if ( intAnswer == 42 )
                break;
        }
        System.exit( 0 );
    }
}