#include <bits/stdc++.h>
using namespace std;
int n, l, v1, v2;
double cl;
double place(double t) {
  cl = 0;
  cl = t * (n + (n - 1) * ((double)v2 - v1) / (v1 + v2));
  return cl * v1 + t * (v2 - v1);
}
int main() {
  int k;
  scanf("%d%d%d%d%d", &n, &l, &v1, &v2, &k);
  n = (n + k - 1) / k;
  double lo = 0, hi = 1e9, mid;
  for (int i = 0; i < 1000; ++i) {
    mid = (lo + hi) / 2;
    if (place(mid) < l)
      lo = mid;
    else
      hi = mid;
  }
  place(hi);
  printf("%.9lf\n", cl);
}
