#include <bits/stdc++.h>
using namespace std;
bool isp(double v1, double v2, long long cp, double t) {
  double x = (1 - t * v1) / (v2 - v1);
  if (x > t) return 0;
  double ls = 0;
  double tm;
  for (long long z = 0; z < (cp); ++z) {
    double l2 = ls + x * v2;
    if (l2 > 1) return 0;
    ls += x * v1;
    tm = (l2 - ls) / (v1 + v2);
    ls += tm * v1;
  }
  return 1;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long n, k;
  double l, v1, v2;
  cin >> n >> l >> v1 >> v2 >> k;
  long long cp = (n + k - 1) / k;
  v1 /= l;
  v2 /= l;
  double mn = 1 / v1;
  double mx = 1 / v2;
  double md;
  for (long long z = 0; z < (80); ++z) {
    md = (mn + mx) / 2;
    if (isp(v1, v2, cp, md))
      mn = md;
    else
      mx = md;
  }
  cout << setprecision(15) << mn << endl;
  return 0;
}
