#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline void ckmax(T& x, T y) {
  x = (y > x ? y : x);
}
template <typename T>
inline void ckmin(T& x, T y) {
  x = (y < x ? y : x);
}
int main() {
  int n, k;
  double l, v1, v2;
  cin >> n >> l >> v1 >> v2 >> k;
  int r = n / k + (n % k != 0);
  double t = l / v2 * (v1 + v2) / (v2 - v1 + 2 * r * v1);
  double ans = (l + t * v1 - t * v2) / v1;
  cout << setiosflags(ios ::fixed) << setprecision(10) << ans << endl;
  return 0;
}
