#include <bits/stdc++.h>
using namespace std;
const double PI = 4 * atan(1);
const long long INF = 1e18;
const int MX = 100001;
int n, k;
long long l, v1, v2;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> l >> v1 >> v2 >> k;
  int num_trips = (n / k);
  if (n % k) num_trips++;
  long double den = v2 * (v2 + v1 + 2 * v1 * (long double)(num_trips - 1));
  cout << setprecision(8);
  long double ans =
      (l / den) * ((v2 + v1) + (long double)(num_trips - 1) * (2 * v2));
  cout << fixed << ans << "\n";
}
