#include <bits/stdc++.h>
using namespace std;
long long n, k;
long double ans, eps = 1e-10, l, v1, v2;
bool solve(long double mid) {
  int x = (n + k - 1) / k;
  long double tl = mid, pos = l;
  while (x--) {
    if (tl < 0) return 0;
    long double trav = (v2 * v1 * tl - v2 * pos) / (v1 - v2);
    if (trav > pos) return 0;
    long double oldTime = tl;
    tl -= trav / v2 + (trav - v1 * trav / v2) / (v1 + v2);
    pos -= v1 * (oldTime - tl);
  }
  return 1;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> l >> v1 >> v2 >> k;
  double long hi = 1e10, lo = 0;
  while (hi - lo >= eps) {
    long double mid = (hi + lo) / 2;
    if (solve(mid)) {
      ans = mid;
      hi = mid - eps;
    } else
      lo = mid + eps;
  }
  cout << setprecision(12) << ans;
  solve(ans);
  return 0;
}
