#include <bits/stdc++.h>
using namespace std;
int n, l, v1, v2, k;
double ls, rs;
double Check(double v) {
  double nowL = v / v2 * v1, nowR = v, pos = v;
  for (int i = 1; i < n; ++i) {
    double tm = (pos - nowL) / (v1 + v2);
    nowL += v1 * tm;
    nowR += v1 * tm;
    pos -= v2 * tm;
    tm = (nowR - pos) / (v2 - v1);
    nowL += v1 * tm;
    nowR += v1 * tm;
    pos += v2 * tm;
  }
  return nowR;
}
int main() {
  scanf("%d%d%d%d%d", &n, &l, &v1, &v2, &k);
  n = (n - 1) / k + 1;
  rs = l;
  while (rs - ls > 1e-6) {
    double mid = (ls + rs) / 2;
    if (Check(mid) <= l)
      ls = mid;
    else
      rs = mid;
  }
  printf("%.10lf", ls / v2 + (l - ls) / v1);
}
