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

/**
 * MyApp is the driver class for Calculator
 */
public class MyApp
{
    /**
     * main is the entry point of the program
     */
    public static void main (String args[])
    {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        Calculator myCalc = new Calculator();

        /* loop reading input lines until the user is finished */
        for (;;)
        {
            System.out.println("Enter rational RPN expression (enter empty line to quit):");
            String line;
            try
            {
                line = in.readLine();
            }
            catch (Exception e)
            {
                System.out.println("Problem reading a line!");
                return;
            }
            if (line.equals(""))
                break;
            myCalc.run(line);
        }
    }
}