#include<bits/stdc++.h>
using namespace std;
double f(){
    string n;
    char c;
    cin>>n;
    c = n[0];
    switch(c){
        case '+':return f() + f();
        case '-':return f() - f();
        case '*':return f() * f();
        case '/':return f() / f();
    }
    return stof(n);
}
int main(){
    printf("%.6lf",f());
    return 0;
}