#include <bits/stdc++.h>
using namespace std;
int n, l, v1, v2, k;
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  long double T = 0;
  long double S = l, t1, t2, d;
  int m = ((n + k - 1) / k);
  S = S / ((long double)(m) - ((long double)(m - 1) * (v2 - v1)) / (v2 + v1));
  t1 = S / v2;
  t2 = (S * (v2 - v1)) / (v2 + v1) / v2;
  T = t1 * m + t2 * (m - 1);
  cout << fixed << setprecision(15) << T;
}
