#include <bits/stdc++.h>
using namespace std;
int main() {
  stack<double> S;
  string x;
  while (cin >> x) {
    istringstream iss(x);
    double r;
    if (iss >> r) {
      S.push(r);
    } else {
      double second = S.top();
      S.pop();
      double first = S.top();
      S.pop();
      double res = first;
      if (x[0] == '+') {
        res += second;
      } else if (x[0] == '-') {
        res -= second;
      } else if (x[0] == '*') {
        res *= second;
      } else {
        res /= second;
      }
      S.push(res);
    }
  }
  cout << fixed << setprecision(2) << S.top() << endl;
}