#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  double L;
  cin >> L;
  double v1;
  cin >> v1;
  double v2;
  cin >> v2;
  int k;
  cin >> k;
  double lo = 0;
  double hi = L / v1;
  int s = n / k + 1;
  if (n % k == 0) s--;
  for (int qq = 0; qq < 100; qq++) {
    double mid = (hi + lo) / 2;
    double alpha = (L - v1 * mid) / (v2 - v1);
    double incr = (L - v1 * mid) / (v2 + v1) + alpha;
    if ((s - 1) * incr + alpha <= mid) {
      hi = mid;
    } else {
      lo = mid;
    }
  }
  printf("%.10f\n", lo);
}
