public class Main {
    public static void main(String[] args) {
        browserscanner scanner;
        try {
            scanner = new browserscanner(new java.io.FileReader("calctest.txt"));
        } catch (Exception e) {
            scanner = new browserscanner(new java.io.InputStreamReader(System.in));
        }
        browserparser parser = new browserparser();
        try {
            parser.yyparse(scanner);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}