#include <bits/stdc++.h>
using namespace std;
const int MAXN = (int)(3000 + 10);
const int INF = (int)(1e9 + 7);
const double EPS = 1e-14;
int n, l, v1, v2, k;
bool can_bus_run(double md);
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  double l1 = 0, r1 = 1. * l / v2;
  int iter = 0;
  while (++iter < 200) {
    double md = (l1 + r1) / 2;
    if (can_bus_run(md)) {
      l1 = md;
    } else {
      r1 = md;
    }
  }
  cout << setprecision(12) << fixed << (l - r1 * v2) / v1 + r1 << endl;
}
bool can_bus_run(double md) {
  double s1 = md * v2;
  double t2 = (1. * l - s1) / v1;
  double t = t2 + md;
  double k2 = n / k + ((n % k) != 0);
  double k3 = n / k - ((n % k) == 0);
  double s3 = md * v2 - md * v1;
  double t3 = s3 / (v1 + v2);
  double bus_time = k2 * md + k3 * t3;
  return t >= bus_time;
}
