#include <bits/stdc++.h>
using namespace std;
long long n, l, v1, v2, k;
double calc(double x2) {
  double x1, ans = 0;
  x1 = (x2 * v2 - v1 * x2) / (v1 + v2);
  return (x2 - x1) * ((n + k - 1) / k - 1) + x2;
}
double bs(double a, double b) {
  if (b - a < 1e-6) return a / v2 + (l - a) / v1;
  double mid = (a + b) / 2;
  if (calc(mid) < l) return bs(mid, b);
  return bs(a, mid);
}
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  cout << setprecision(9) << fixed << bs(0, l) << endl;
  return 0;
}
