#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-7;
int main() {
  int n, l, v1, v2, k;
  scanf("%d%d%d%d%d", &n, &l, &v1, &v2, &k);
  n = (n + k - 1) / k;
  double ans = 0.0;
  double t = ((double)l * (v1 + v2)) / ((double)n * ((double)v1 + v2) -
                                        ((double)n - 1) * ((double)v2 - v1));
  t /= v2;
  ans = n * t + (((n - 1) * t * (v2 - v1)) / (v1 + v2));
  printf("%0.10lf\n", ans);
  return 0;
}
