options { LOOKAHEAD=2; }

PARSER_BEGIN(Calculatrice)
public class Calculatrice
{
    public static void main(String args[]) throws ParseException 
    {
        Calculatrice parser = new Calculatrice(System.in);
        System.out.println(parser.expression());
    }
}
PARSER_END(Calculatrice)

SKIP : { " " | "\r" | "\t" | "\n" }

TOKEN:
{
    < NUMBER: (<DIGIT>)+ >
|   < DIGIT: ["0"-"9"] >
}

int expression():
{ int a,b; }
{
  a=terme()
  (
    "+" b=expression() { a += b; }
  )* { return a; }
}

int terme():
{ int a,b; }
{
  a=element()
  (
    "*" b=terme() { a *= b; }
  )* { return a; }
}

int element():
{ Token t; }
{
    t=<NUMBER>             { return Integer.parseInt(t.toString()); }
}