文件目录

#include <bits/stdc++.h>
using namespace std;
double f()
{
    char s[1000];
    cin >> s;
    if (s[0] == '+')
        return f() + f();
    else if (s[0] == '-')
        return f() - f();
    else if (s[0] == '*')
        return f() * f();
    else if (s[0] == '/')
        return f() / f();
    else
        return atof(s);
}
int main()
{
    printf("%f\n", f());
    return 0;
}