#include <bits/stdc++.h>
using namespace std;
int n, k;
double l, v1, v2;
bool can(double ttime) {
  int temp = n;
  double d = ((ttime * v1 * v2) - (v2 * l)) / (v1 - v2), td = d / v2;
  while (temp > 0) {
    temp -= k;
    ttime -= td;
    if (temp <= 0) goto finish;
    ttime -= (d - td * v1) / (v1 + v2);
    if (ttime < 0) goto finish;
  }
finish:
  return (ttime >= 0.0);
}
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  int gp = n / k;
  gp += (n % k != 0);
  double d = ((v1 + v2) * l) / (2 * gp * v1 + v2 - v1);
  double t = d / v2 + (l - d) / v1;
  printf("%.10f\n", t);
  return 0;
}
