#include <bits/stdc++.h>
using namespace std;
void SO() { cout << endl; }
template <typename S, typename... Strings>
void SO(S x, const Strings &...rest) {
  cout << x << ' ';
  SO(rest...);
}
const long double PI = 3.1415926535897932384626433832795;
const int v5 = 100000;
const int v9 = 1000000000;
const int v6 = 1000000;
inline long long int ABS(long long int a) {
  if (a < 0) return (-a);
  return a;
}
inline long long int min(long long int a, long long int b, long long int c) {
  return min(a, min(b, c));
}
inline long long int max(long long int a, long long int b, long long int c) {
  return max(a, max(b, c));
}
inline void AI(long long int x[], long long int n) {
  for (long long int i = 0; i < (n); ++i) cin >> (x[i]);
}
inline void VI(vector<long long int> &arr, long long int n) {
  for (long long int i = 0; i < (n); ++i) {
    long long int x;
    cin >> (x);
    arr.push_back(x);
  };
}
long int n, k;
long double c = 0, l, v1, v2;
long long int a[4000001];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> l;
  cin >> v1 >> v2 >> k;
  long int trips = n / k + (n % k == 0 ? 0 : 1);
  long double trp = trips;
  c = l / ((2 * (trp - 1) * v1 / (v1 + v2)) + 1);
  cout << fixed << setprecision(10) << (c / v2) + ((l - c) / v1) << "\n";
  return 0;
}
