#include <bits/stdc++.h>
using namespace std;
int main() {
  long double n, l, v1, v2, k;
  cin >> n;
  cin >> l;
  cin >> v1;
  cin >> v2;
  cin >> k;
  int rounds = ceil(n / k);
  long double d = l / (((2 * v1) / (v1 + v2)) * (rounds - 1) + 1);
  long double time = (((l - d) / v1) + d / v2);
  cout << setprecision(30) << time;
}
