#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1);
int main() {
  int n, k;
  double l, v1, v2, dist = 0;
  cin >> n >> l >> v1 >> v2 >> k;
  int cnt = (n + k - 1) / k;
  double x = (double(cnt) * 2 - 1);
  double ans = l * (x * v2 + v1);
  ans /= (v2 + x * v1) * v2;
  cout << setprecision(9) << fixed;
  cout << ans << endl;
}
