public class VisitTest {

    public static void main(String args[]) {

        prefix parser;
        ASTExpression tree;
        Calculate calc = new Calculate();
        PrintTree pt = new PrintTree();
        
        parser = new prefix(System.in);
        try {
            tree = parser.expression();
            System.out.println("Tree:");
            tree.accept(pt);
            System.out.println("Value:");
            System.out.println(tree.accept(calc));
        } catch (ParseException e) {
            System.out.println(e.getMessage());
            System.out.println("Parsing Failed");
        }
    }

}