#include <bits/stdc++.h>
using namespace std;
inline int IN() {
  char c;
  register int first = 0;
  for (; (c = getchar()) < 48 && c ^ '-' || c > 57;)
    ;
  bool f = c == '-';
  if (f) (c = getchar());
  for (; c > 47 && c < 58; (c = getchar()))
    first = (first << 3) + (first << 1) + c - 48;
  if (f) first = -first;
  return first;
}
inline void glance() { freopen("ha.in", "r", stdin); }
int n, k;
double L, v1, v2, ans;
inline double calc(double first) {
  double T = first / v2, pos = first, now = T * v1;
  int n = ::n - k;
  for (; n > 0; n -= k) {
    double t = (pos - now) / (v1 + v2);
    T += t;
    pos += t * v1;
    now += t * v1;
    t = (pos - now) / (v2 - v1);
    T += t;
    pos += t * v1;
    now += t * v1;
  }
  return T;
}
int main() {
  scanf("%d%lf%lf%lf%d", &n, &L, &v1, &v2, &k);
  if (k >= n) return printf("%.10lf\n", L / v2), 0;
  double l = 0, r = L;
  for (int _r = 100, i = 1; i < _r; ++i) {
    double m = (l + r) / 2;
    double T = m / v2 + (L - m) / v1;
    if (calc(m) < T)
      l = m;
    else
      r = m;
  }
  printf("%.10lf\n", calc(l));
}
