#include <bits/stdc++.h>
using namespace std;
long long n, l, v1, v2, k;
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  long long g = (n + k - 1) / k;
  double le = 0, ri = l / (double)v1;
  while ((ri - le) >= 5e-7) {
    double mid = (le + ri) / 2;
    double t = 0;
    for (int i = 1; i <= g; i++) {
      double x = ((double)l - v1 * mid) / (v2 - v1);
      t += x;
      if (i != g) {
        double y = x * (v2 - v1) / (v1 + v2);
        t += y;
      }
    }
    if (mid > t)
      ri = mid;
    else
      le = mid;
  }
  cout << setprecision(9) << le << endl;
  return 0;
}
