#include <bits/stdc++.h>
using namespace std;
int k, n;
double v1, v2, l;
double f(double t) {
  double beg = 0.0;
  int p = n;
  double bdist = 0, pdist = 0;
  while (1) {
    p -= k;
    bdist = beg + t * v2;
    pdist = beg + t * v1;
    double trv = (bdist - pdist) / (v1 + v2);
    beg = pdist + trv * v1;
    if (p <= 0) {
      break;
    }
  }
  return bdist;
}
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  double left = 0, right = l;
  double EPS = 1e-9;
  for (int i = 0; i < 1000; i++) {
    double m = (left + right) / 2.0;
    if (f(m) < l) {
      left = m;
    } else {
      right = m;
    }
  }
  printf("%lf", right + (l - v2 * right) / v1);
  return 0;
}
