import java.util.*;
import java.lang.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.lang.Throwable.*;

public class Final{
    public static void main(String[]args){

Scanner in = new Scanner (System.in);
System.out.print("Enter: ");
String s = in.nextLine();


        int pipe[] = new int [s.length()];
        int index = 0;

        for(int i =0; i < s.length(); i++)
        {


            // strip out white spaces
            if (Character.isDigit(s.charAt(i))) {
                int n = 0;

                do {
                    n = n * 10 + s.charAt(i) - (int) '0';
                    i++;
                }
                while (Character.isDigit(s.charAt(i)));

                pipe[index] = n;
                System.out.println("index= " + index);
                System.out.println(pipe[index]);
                index ++;


             }
              else if (s.charAt(i) == '+'){

                System.out.println("index= " + index);
                System.out.println("+");
                pipe[index-2] = pipe[index-2] + pipe[index-1];
                System.out.println("r: " + pipe[index-2]);
                index = index - 1;

                }
            else if (s.charAt(i) == '-'){

                System.out.println("index= " + index);
                    System.out.println("-");
                pipe[index-2] = pipe[index-2] - pipe[index-1];

                System.out.println("r: " + pipe[index-2]);
                index = index - 1;
                }
                else if (s.charAt(i) == '*'){
                System.out.println("index= " + index);  System.out.println("*");

                pipe[index-2] = pipe[index-2] * pipe[index-1];

                System.out.println("r: " + pipe[index-2]);
                    index = index - 1;
                }
                else if (s.charAt(i) == '/'){

                System.out.println("index= " + index);  System.out.println("/");
                pipe[index-2] = pipe[index-2] / pipe[index-1];

                System.out.println("r: " + pipe[index-2]);
                    index = index - 1;
                }
        }




    }
}