#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, l, v1, v2, k, t1, t2, t;
  cin >> n >> l >> v1 >> v2 >> k;
  int m = (n + k - 1) / k;
  t2 = l / (v2 + v1 * (m - 1) * (2 * v2) / (v1 + v2));
  t = t2 + (2 * v2 / (v1 + v2)) * (m - 1) * t2;
  printf("%.10lf\n", t);
  return 0;
}
