#include <stdexcept> // for access to logic_error
#include <iostream>
#include <stack>

using namespace std;

class Expr
{
public:
  Expr() = default;
  virtual ~Expr() = default;
  
  virtual double evaluate() const = 0;
  virtual void print(ostream& os) const = 0;
};

class Operand : public Expr
{
public:
  Operand(double d) : value{d} {}
  
  double evaluate() const { return value; }
  void print(ostream& os) const { os << value; }
  
private:
  double value;
};

class Operator : public Expr
{
public:
  Operator(Expr* l, Expr* r) : Expr(), left{l}, right{r} {}
  Operator() = default;
  ~Operator() { delete right; delete left; }
  
  virtual double evaluate() const = 0;
  virtual void print(ostream& os) const {
    os << '(';
    left->print(os);
    os << symbol();
    right->print(os);
    os << ')';
  }
  
protected:
  virtual char symbol() const = 0;
  
  Expr* left;
  Expr* right;
};

class Plus : public Operator
{
public:
  Plus(Expr* l, Expr* r) : Operator(l, r) {}
  ~Plus() = default;
  
  double evaluate() const {
    return left->evaluate() + right->evaluate();
  }
protected:
  virtual char symbol() const { return '+'; };
};

class Mult : public Operator
{
public:
  Mult(Expr* l, Expr* r) : Operator(l, r) {}
  ~Mult() = default;
  
  double evaluate() const {
    return left->evaluate() * right->evaluate();
  }
protected:
  virtual char symbol() const { return '*'; };
};


Expr* top_and_pop(stack<Expr*>& s)
{
  if ( s.empty() )
    throw logic_error{"Too few operands"};
  
  Expr* e{ s.top() };
  s.pop();
  return e;
}

int main()
{
  stack<Expr*> exprs;
  string input;
  while ( cin >> input )
  {
    switch( input.at(0) )
    {
      case '+':
      {
        Expr* right{ top_and_pop( exprs ) };
        Expr* left{ top_and_pop( exprs ) };
        exprs.push( new Plus{left, right} );
      }
      break;
      
      case '*':
      {
        Expr* right{ top_and_pop( exprs ) };
        Expr* left{ top_and_pop( exprs ) };
        exprs.push( new Mult{left, right} );
      }
      break;
        
      default:
      {
        exprs.push( new Operand{ stod(input) } );
      }
      break;        
    }
  }

  Expr* e{ exprs.top() };
  e->print( cout );
  cout << endl << "Answer: " << e->evaluate() << endl;

  while ( ! exprs.empty() )
  {
    delete top_and_pop( exprs );
  }
  
  return 0;
}