#include <iostream>
#include <istream>
#include <string>
#include <sstream>
#include <stack>

struct Token
{
  bool isNumber;
  union {
    int number;
    char operation;
  };
  Token() {}
  Token(int value):isNumber(true), number(value){} 
  Token(char op)  :isNumber(false), operation(op){}
};
bool is_operator(char c){
  switch(c){
    case '+':
    case '-':
    case '*':
    case '/':
    case '%':
    case 'p':
    case 'd':
    case 'c':
    case 'x':
    case 'q':
    return true;
    default: return false;
  }
}
std::istream& operator>>(std::istream& is, Token & token){
  std::string s;
  if (!(is >> s)) {
    return is;
  }
  if (s.length() == 1 && is_operator(s[0])){
    token = Token(s[0]);
    return is;
  }
  std::istringstream ss(s);
  int i;
  if (!(ss >> i)) {
    return is;
  } 
  token = Token(i);
  return is;
}

int main() {
  std::stack<int> s;
  Token t;
  while(std::cin >> t){
    if (t.isNumber) {
      s.push(t.number);
      continue;
    }

#define EXPAND_OPERATOR_IF(OPERATOR) \
    if (t.operation == #OPERATOR[0]) { \
      if (s.size() < 2) { \
        std::cerr << "Operation " #OPERATOR " error" << std::endl; \
        continue; \
      } \
      auto a = s.top(); \
      s.pop(); \
      auto b = s.top(); \
      s.pop(); \
      s.push(b OPERATOR a); \
      continue; \
    }

    EXPAND_OPERATOR_IF(+)
    EXPAND_OPERATOR_IF(-)
    EXPAND_OPERATOR_IF(*)
    EXPAND_OPERATOR_IF(/)
    EXPAND_OPERATOR_IF(%)
#undef EXPAND_OPERATOR_IF
#define EXPAND_OPERATION(OPERATOR, ELEMS, CODE) \
    if (t.operation == OPERATOR){ \
      if (s.size() < ELEMS) { \
        std::cerr << "Operation " #OPERATOR " error"<< std::endl;\
        continue;\
      }\
      CODE;\
      continue;\
    }

    EXPAND_OPERATION('p', 1, std::cout << s.top() << std::endl);
    EXPAND_OPERATION('d', 1, s.pop());
    EXPAND_OPERATION('x', 2, 
    {int a = s.top();
      s.pop();
      int b = s.top();
      s.pop();
      s.push(a);
      s.push(b);});
    EXPAND_OPERATION('c', 1, s.push(s.top()));
    EXPAND_OPERATION('q', 0, break);
#undef EXPAND_OPRATION
  }
}