#include <bits/stdc++.h>
using namespace std;
template <class T, class U>
inline void Max(T &a, U b) {
  if (a < b) a = b;
}
template <class T, class U>
inline void Min(T &a, U b) {
  if (a > b) a = b;
}
inline void add(int &a, int b) {
  a += b;
  while (a >= 1000000007) a -= 1000000007;
}
int pow(int a, int b) {
  int ans = 1;
  while (b) {
    if (b & 1) ans = ans * (long long)a % 1000000007;
    a = (long long)a * a % 1000000007;
    b >>= 1;
  }
  return ans;
}
int main() {
  int i, j, m = 0, n, k;
  int v1, v2, L;
  scanf("%d%d%d%d%d", &n, &L, &v1, &v2, &k);
  double l = L * 1. / v2, r = L * 1. / v1;
  const double eps = 1e-10;
  for (int it = 0; it < 60; it++) {
    double t = (l + r) / 2;
    if (v1 * t >= L) {
      r = t - eps;
      continue;
    }
    double at = 0, tt = (L - v1 * t) / (v2 - v1), T = 0;
    at = 1. * (v2 - v1) / (v2 + v1) * tt;
    j = n / k;
    T = j * tt + (j - 1) * at;
    if (n % k) T += tt + at;
    if (T >= t + eps) {
      l = t + eps;
      continue;
    }
    r = t - eps;
  }
  printf("%.6lf\n", r + eps);
  return 0;
}
