#include <bits/stdc++.h>
const int MAXINT = 2147483640;
const long long MAXLL = 9223372036854775800LL;
const long long MAXN = 1000000;
const double pi = 3.1415926535897932384626433832795;
using namespace std;
double s, v1, v2;
long long n, kol;
long long check(double xx) {
  long long sum = 0;
  double anstime = 0, vk, s1, s2, tin, s3;
  while (1) {
    s3 = s - v1 * anstime;
    vk = (s3 - (xx - anstime) * v1) / (v2 - v1);
    anstime += vk;
    sum += kol;
    if (sum >= n) break;
    s2 = vk * v2 + (anstime - vk) * v1;
    s1 = anstime * v1;
    tin = (s2 - s1) / (v1 + v2);
    anstime += tin;
    if (anstime > xx) return 0;
  }
  if (xx - anstime >= 0)
    return 1;
  else
    return 0;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  srand(time(0));
  double time, kolend, s1, t1, s2, l, r, c;
  cin >> n >> s >> v1 >> v2 >> kol;
  l = 0;
  r = s / v1 + 1;
  while (r - l > 1e-6) {
    c = (l + r) / 2;
    if (check(c))
      r = c;
    else
      l = c;
  }
  cout << fixed << setprecision(7) << l << endl;
  return 0;
}
