Assignemnt #73 Baby Calculator

Code
/// Name: Yordan Rashkov
/// Period: 7
/// Program Name: Baby Calculator
/// File Name: BabyCalculator.java
/// Date Finished: 1/14/2016

import java.util.Scanner;

public class BabyCalculator
{
    public static void main( String[] args )
    {
        Scanner keyboard = new Scanner(System.in);
        
        double a, b, c;
        String L;
        
        do
        {
            System.out.print("> ");
            a = keyboard.nextDouble();
            L = keyboard.next();
            b = keyboard.nextDouble();
            
            if ( L.equals("+") )
            {
                c = a + b;
            }
            else if ( L.equals("-") )
            {
                c = a - b;
            }
            else if ( L.equals("*") )
            {
                c = a * b;
            }
            else if ( L.equals("/") )
            {
                c = a / b;
            }
                else 
                {
                    System.out.println( "Undefined operator: ' " + L + " '. ");
                    c = 0;
        }
        
        System.out.println(c);
        } while ( a != 0 );
    }
}