import java.io.InputStreamReader;
import java.io.Reader;

import symbols.*;

/**
 * Parse simple binary expressions with parantheses
 *
 * @author NN
 * @version 2008-xx-yy
 */
public class Parser {
	private SymbolReader symbolReader;

	public Parser( Reader inStream ) {
		symbolReader = new SymbolReader(inStream);
	}

	public Expression parse() throws SyntaxError {
		return parseExpression(symbolReader.readNextSymbol());
	}
	private Expression parseExpression(Symbol s) throws SyntaxError{

//		if (s.getType()==SymbolTypes.EOL)
//			System.out.println("EOL");
		if(s.getType()==SymbolTypes.VALUE){
			System.out.println("if");
			return new ConstantExpression(s.getValue());

		}


		else if(s.getType()==SymbolTypes.LPAREN){
			Expression e =parseExpression(symbolReader.readNextSymbol());
			Symbol x = symbolReader.readNextSymbol();
			if(x.getType()==SymbolTypes.RPAREN){
				return e;
			}
			else{

				e=parseBinary(e,x);
				//if(symbolReader.readNextSymbol().getType()==SymbolTypes.RPAREN)
					return e;
//				else
//					return null;
			}

		}
		else {//if (s.getType()==SymbolTypes.RPAREN)

			System.out.println("else");
			return parseExpression(s);
		}



		//return new ConstantExpression( 0);
	}
	private Expression parseBinary(Expression s, Symbol t) throws SyntaxError{
		System.out.println("Binary");
		return new BinaryExpression(s,t.getType(),parseExpression(symbolReader.readNextSymbol()));
	}
	//	private Expression parseBinary(Symbol s,Symbol t) throws SyntaxError{
	//		return new BinaryExpression(parseExpression(s),t.getType(),parseExpression(symbolReader.readNextSymbol()));
	//	}

	public static void main(String[]arg){
		Parser p = new Parser(new InputStreamReader(System.in));
		try {
			Expression e = p.parse();

			//e.prettyInfix();
			System.out.println(e.getValue());
		} catch (SyntaxError e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}