#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3fLL;
long long N, L, v1, v2, k;
long long d;
pair<double, double> get_it(double mid) {
  double end = mid * v2;
  double pass = mid;
  for (int i = 1; i < d; i++) {
    double add = (end - pass * v1) / (v2 + v1);
    end = (pass + add) * v1 + mid * v2;
    pass += add + mid;
  }
  return {pass, end};
}
bool check(double mid) { return (get_it(mid).second >= L); }
void test_case() {
  cin >> N >> L >> v1 >> v2 >> k;
  d = (N + k - 1) / k;
  double l = 0, r = INF;
  for (int i = 0; i < 100; i++) {
    double m = l + (r - l) / 2;
    if (check(m))
      r = m;
    else
      l = m;
  }
  cout << fixed << setprecision(10);
  cout << get_it(l).first << '\n';
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int tt = 1;
  while (tt--) {
    test_case();
  }
  return 0;
}
