import niceIO.niceInputStream;
import easy.Stdio;
import java.util.Stack;
//import java.util.Math;

public class art {

  private static niceInputStream in;
  private static Stack  ops, arg;

  public static void main(String argv[]) {
    in= new niceInputStream(System.in);
    ops= new Stack(); arg= new Stack();
    art a= new art();
  }

  public art() {
    char c, o;
    ask("Expr: ");
    o= in.tegnNS();
    while (o != 'q') {
      while( o != '\n' && o != '\r' && o != 'q') {
      if (o == '+') push(arg,'+');
      else if (o == '-') push(arg,'-');
      else if (o == '/') push(arg,'/');
      else if (o == '*') push(arg,'*');
      else if (o == '^') push(arg,'^');
      else {in.unread(); pushs(arg,in.htall()); }
      o= in.tegnNS();
    }
    while (!arg.empty()) { push(ops,pops(arg)); }
    askl(eval());
    }
}

  private int eval() {
    String s= pops(ops); int z=0;
    if (isInt(s)) z=intOf(s);
    else {
      if (s.equals("+")) { int a1= eval(); int a2= eval(); z= a1+a2;
	ask(a1); ask("+"); askl(a2);
      }
      else if (s.equals("*")) {	int a1= eval(); int a2= eval(); z= a1*a2;
	ask(a1); ask("*"); askl(a2);
      }
      else if (s.equals("/")) {	int a2=eval(); int a1=eval(); z= a2/a1;
	ask(a2); ask("/"); askl(a1);
      }
      else if (s.equals("-")) { int a2=eval(); int a1=eval(); z= a2-a1;
	ask(a2); ask("-"); askl(a1);
      }
      else if (s.equals("^")) { int a2=eval(); int a1=eval(); z= (int)Math.pow(a2,a1);
	ask(a2); ask("^"); askl(a1);
      }
    }
    return z;
  }
  private int intOf(String s) { return Integer.parseInt(s);}
  private boolean isInt(String s) { return Character.isDigit(s.charAt(0)); }

  private void askl(String s) { Stdio.promptln(s);}
  private void askl(int i) { Stdio.promptln(i);}
  private void ask(String s) { Stdio.prompt(s);}
  private void ask(int i) { Stdio.prompt(i);}
  
  private void push(Stack s, char c)   { s.push(new String(new Character(c).toString())); }
  private void push(Stack s, int c)    { s.push(new Integer(c)); }
  private void push(Stack s, String c) { s.push(new String(c)); }
  private void pushs(Stack s, int c)   { s.push(Integer.toString(c)); }

  private int popi(Stack s) { return ((Integer)s.pop()).intValue(); }
  private String pops(Stack s) { return (String)s.pop(); }

  private int peeki(Stack s) { return ((Integer)s.peek()).intValue(); }
  private String peeks(Stack s) { return (String)s.peek(); }

}