#include <bits/stdc++.h>
using namespace std;
int n, l, v1, v2, k;
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  n = (n + k - 1) / k;
  double t = l / (1.0 * v2 +
                  (1.0 * n - 1) * (1.0 * 2 * v1 * v2) / (1.0 * v1 + 1.0 * v2));
  t += (l - t * v2) / v1;
  cout << fixed << setprecision(8) << t << endl;
}
