/***********************************************************************************
* Freeman Lo
* 
* This interpreter.java file interpretes assembler code which generated from
* the Compiler.java and does its math stuff to get an answer to print off to screen.
*
*************************************************************************************/

import java.io.*;
import java.util.*;

class Overflow extends Exception
{
}

class Underflow extends Exception
{
}

class Interpreter {

	public static void main ( String [] args ) throws IOException {
		// this allows the use of the redirection symbol <
		BufferedReader br=null;
		br = new BufferedReader( new InputStreamReader(System.in));

		// this allows the use of the redirection symbol >
		BufferedWriter bw = null;
		bw = new BufferedWriter( new OutputStreamWriter(System.out));

		Scanner scan = new Scanner(System.in);

		String line="",numString="",tempString="";
		int num1=0,num2=0,total=0;
		StringTokenizer token=null;
		Object x=null;
		Object y=null;

		// manually creating the stack obj
		Stack stak = new Stack(); // max_size = 64 unless i specify

		while ( (line=br.readLine()) != null ) {
			// if it sees the mul, add, div, sub
			if ( line.equalsIgnoreCase("mul") == true ||
				line.equalsIgnoreCase("div") == true ||
				line.equalsIgnoreCase("add") == true ||
				line.equalsIgnoreCase("sub") == true ||
				line.equalsIgnoreCase("prtpop") == true ) {

				if ( line.equalsIgnoreCase("add") == true ) {
					x = stak.topAndPop(); // top most
					y = stak.topAndPop(); // second most
				token = new StringTokenizer(x.toString());
					token.nextToken();
					numString = token.nextToken();
					num1 = Integer.parseInt(numString);
				token = new StringTokenizer(y.toString());
					token.nextToken();
					numString = token.nextToken();
					num2 = Integer.parseInt(numString);
			// calculate then push it back to the stack
				total = num1 + num2;
					tempString = "push " + total;
				try {
					stak.push(tempString);
				} catch ( Overflow of){
				}

				} else
				if ( line.equalsIgnoreCase("sub") == true ) {

					x = stak.topAndPop(); // top most
					y = stak.topAndPop(); // second most
				token = new StringTokenizer(x.toString());
					token.nextToken();
					numString = token.nextToken();
					num1 = Integer.parseInt(numString);
				token = new StringTokenizer(y.toString());
					token.nextToken();
					numString = token.nextToken();
					num2 = Integer.parseInt(numString);
				// calculate then push it back to the stack
				total = num2 - num1;
					tempString = "push " + total;
				try {
					stak.push(tempString);
				} catch ( Overflow of){
				}

				} else
				if ( line.equalsIgnoreCase("mul") == true ) {

					x = stak.topAndPop(); // top most
					y = stak.topAndPop(); // second most
				token = new StringTokenizer(x.toString());
					token.nextToken();
					numString = token.nextToken();
					num1 = Integer.parseInt(numString);
				token = new StringTokenizer(y.toString());
					token.nextToken();
					numString = token.nextToken();
					num2 = Integer.parseInt(numString);
				// calculate then push it back to the stack
				total = num1 * num2;
					tempString = "push " + total;
				try {
					stak.push(tempString);
				} catch ( Overflow of){
				}

				} else
				if ( line.equalsIgnoreCase("div") == true ) {

					x = stak.topAndPop(); // top most
					y = stak.topAndPop(); // second most
				token = new StringTokenizer(x.toString());
					token.nextToken();
					numString = token.nextToken();
					num1 = Integer.parseInt(numString);
				token = new StringTokenizer(y.toString());
					token.nextToken();
					numString = token.nextToken();
					num2 = Integer.parseInt(numString);
				// calculate then push it back to the stack
				total = num2 / num1;
					tempString = "push " + total;
				try {
					stak.push(tempString);
				} catch ( Overflow of){
				}

				} else
				if ( line.equalsIgnoreCase("prtpop") == true ) {
					System.out.println(total);
				}

			} // end big if
			else {// add to stack

			try {
				stak.push(line);
			} catch(Overflow of) {
			}

			}

		}// end while
	} // end main
} // end class