import java.io.*;
import AST;
public class CalcAST
{ private static StreamTokenizer tokens;
  private static int ahead;
  public static void main(String argv[]) throws IOException
  { InputStreamReader reader = new InputStreamReader(System.in);
    tokens = new StreamTokenizer(reader);
    tokens.ordinaryChar('.');
    tokens.ordinaryChar('-');
    tokens.ordinaryChar('/');
    get();
    AST ast = expr();
    if (ahead == (int)'$')
      ast.toLisp();
    else
      System.out.println("Syntax error");
  }
  private static void get() throws IOException
  { ahead = tokens.nextToken();
  }
  private static AST expr() throws IOException
  { AST subtotal = term();
    return term_tail(subtotal);
  }
  private static AST term_tail(AST subtotal) throws IOException
  { if (ahead == (int)'+')
    { get();
      AST termvalue = term();
      return term_tail(new AST('+', subtotal, termvalue));
    }
    else if (ahead == (int)'-')
    { get();
      AST termvalue = term();
      return term_tail(new AST('-', subtotal, termvalue));
    }
    else
      return subtotal;
  }
  private static AST term() throws IOException
  { AST subtotal = factor();
    return factor_tail(subtotal);
  }
  private static AST factor_tail(AST subtotal) throws IOException
  { if (ahead == (int)'*')
    { get();
      AST factorvalue = factor();
      return factor_tail(new AST('*', subtotal, factorvalue));
    }
    else if (ahead == (int)'/')
    { get();
      AST factorvalue = factor();
      return factor_tail(new AST('/', subtotal, factorvalue));
    }
    else
      return subtotal;
  }
  private static AST factor() throws IOException
  { if (ahead == (int)'(')
    { get();
      AST ast = expr();
      if (ahead == (int)')')
        get();
      else
        System.out.println("closing ) expected");
      return ast;
    }
    else if (ahead == (int)'-')
    { get();
      return new AST('%', factor());
    }
    else if (ahead == tokens.TT_WORD)
    { get();
      return new AST(0);
    }
    else if (ahead == tokens.TT_NUMBER)
    { get();
      return new AST((int)tokens.nval);
    }
    else
    { System.out.println("factor expected");
      return new AST(0);
    }
  }
}