package M03Java_Advanced.C01Java_Advanced.L01Stacks_and_Queues.Stacks_and_Queues_Exercises;

import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;
import java.util.Stack;

public class E09InfixToPostfix {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        List<Character> result = new LinkedList<>();
        Stack<Character> stack = new Stack<>();
        String[] input = sc.nextLine().split(" ");

        for (String s : input) {
            char ch = s.charAt(0);

            if (Character.isLetterOrDigit(ch)) {
                result.add(ch);

            } else if (ch == '(') {
                stack.push(ch);

            } else if (ch == ')') {

                while (!stack.isEmpty() && stack.peek() != '(') {
                    result.add(stack.pop());
                }

                stack.pop();

            } else {

                while (!stack.isEmpty() && precedence(ch) <= precedence(stack.peek())) {
                    result.add(stack.pop());
                }

                stack.push(ch);
            }
        }

        while (!stack.isEmpty()){
            result.add(stack.pop());
        }

        System.out.println(result.toString().replaceAll("[\\[\\],]", ""));
    }

    private static int precedence(char ch)
    {
        switch (ch)
        {
            case '+':
            case '-':
                return 1;

            case '*':
            case '/':
                return 2;

            case '^':
                return 3;
        }
        return -1;
    }
}