import java.util.Stack;

/**
 * Odwrotna Notacja Polska
 * www.algorytm.org (c) 2006
 * @author Tomasz Lubiński
 *
 */

public class ONP {
	
	static Stack stack = new Stack();


	/**
	 * Main method
	 * @param args
	 */
	@SuppressWarnings("unchecked")
	public static void main(String[] args) {
		String result = "";
		String statement = "";
		boolean sign = true; //indicates that - is a number sign (not operator minus)
		
		System.out.println("Podaj wyrażenie:");
		statement = Console.readString();
		//remove spaces from statement
		statement = statement.replaceAll(" ","");
		
		//process all characters
		for (int i=0; i<statement.length(); i++) {
			if (statement.charAt(i) == '(') {
				stack.push("(");
				sign = true;
				result += " ";
			} else if (statement.charAt(i) == ')') {
				result += " " + getFromStackUntilBracket();
				sign = false;
			} else if ((statement.charAt(i) == '+' ||
					    statement.charAt(i) == '-' ||
					    statement.charAt(i) == '*' ||
					    statement.charAt(i) == '/') && !sign) {
				result += " " + getFromStack(statement.substring(i, i+1));
				sign = true;
			} else {
				if (sign && statement.charAt(i) == '-') {
					result += " ";
				}
				result += statement.charAt(i);
				sign = false;				
			}
		}
		result += getAllFromStack();
		result = result.replaceAll("  ", " ");
		
		System.out.println("ONP:" + result);
	}

	/**
	 * Gets all operators until bracket from stack
	 * @return
	 */
	private static String getFromStackUntilBracket() {
		String result = "";
		String c = null;
		if (!stack.empty()) {
			c = (String) stack.pop();
			while (!c.equals("(")){
				result = result + " " + c;
				if (stack.empty()) break;
				c = (String) stack.pop();
			}
		}
		if (result.length() > 0) {
			result = " " + result;
		}
		return result;
	}

	/**
	 * Gets all operators with priority less or equal to oeprator from stack
	 * @param operator
	 * @return
	 */
	@SuppressWarnings("unchecked")
	private static String getFromStack(String operator) {
		String result = "";
		String c = null;
		if (!stack.empty()) {
			c = (String) stack.pop();
			while (((operator.equals("+") || operator.equals("-")) && !c.equals("(")) ||
			   	   ((operator.equals("/") || operator.equals("*")) && (c.equals("/") || c.equals("*")))){
				result += " " + c;
				if (stack.empty()) break;
				c = (String) stack.pop();
			}
			stack.push(c);
		}
		stack.push(operator);
		
		return result;
	}
	
	/**
	 * Get all from stack
	 * @return
	 */
	private static String getAllFromStack() {
		String result = "";
		String c = null;
		while (!stack.empty()){
			c = (String) stack.pop();
			result += " " + c;
		}
		return result;
	}	

}