#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, l, v1, v2, k, time;
  double s, s1, s2, ss, t;
  cin >> n >> l >> v1 >> v2 >> k;
  if (n % k == 0)
    time = n / k;
  else
    time = n / k + 1;
  s = (double)time * (v1 + v2) / (v2 - v1) - (time - 1);
  s2 = l / s;
  s1 = s2 * (v1 + v2) / (v2 - v1);
  ss = time * s1 + (time - 1) * s2;
  t = ss / v2;
  cout << fixed << setprecision(10) << t << endl;
  return 0;
}
