import java.util.*;
public class Main 
{   
    //定义一个数组进行存储
    static String[] arr;
    static int i = -1;
    //进行判断
        private static double exp() {
            i++;
            switch (arr[i]) {
            case "+":
                return exp() + exp();
            case "-":
                return exp() - exp();
            case "*":
                return exp() * exp();
            case "/":
                return exp() / exp();
            default:
                return Double.parseDouble(arr[i]);
            }
        }

    //测试代码
    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);
        Main m = new Main();
        String str1 = sc.nextLine();
         arr = str1.split(" ");
        //输出答案
        System.out.println(m.exp());
    }
}