// unordered_map::find
#include <iostream>
#include <string>
#include <unordered_map>
#include <cmath>
#include <stack>
#include <map>
#include<stdarg.h>

std::string delimiter = " ";
std::stack<double> evaluator;

void parse(std::string token, double value) {
    if (token == "x") {
        evaluator.push(value);
        return;
    }
    if (token == "*") {
        double a = evaluator.top();
        evaluator.pop();
        double b = evaluator.top();
        evaluator.pop();
        evaluator.push(a * b);
    }
    else if (token == "/") {
        double a = evaluator.top();
        evaluator.pop();
        double b = evaluator.top();
        evaluator.pop();
        evaluator.push(b / a);
    } else if (token == "+") {
        double a = evaluator.top();
        evaluator.pop();
        double b = evaluator.top();
        evaluator.pop();
        evaluator.push(a + b);
    }
    else if (token == "-") {
        double a = evaluator.top();
        evaluator.pop();
        double b = evaluator.top();
        evaluator.pop();
        evaluator.push(b - a);
    }
    else if (token == "cos") {
        double a = evaluator.top();
        evaluator.pop();
        evaluator.push(cos(a));
    }
    else if (token == "sin") {
        double a = evaluator.top();
        evaluator.pop();
        evaluator.push(sin(a));
    }
    else evaluator.push(std::stod(token));
}

double split(std::string s, double value) {
    size_t pos = 0;
    std::string token;
    while ((pos = s.find(delimiter)) != std::string::npos) {
        token = s.substr(0, pos);
        parse(token, value);
        s.erase(0, pos + delimiter.length());
    }
    return evaluator.top();

}

int main() {

    std::string s;
    std::getline(std::cin, s);
    s += delimiter;

    std::string d;
    std::getline(std::cin, d);
    double xvalue = std::stod(d);

    std::cout << split(s, xvalue);
    return 0;
}