#include <bits/stdc++.h>
using namespace std;
int n, k;
double l, v1, v2;
int p;
int main() {
  scanf("%d %lf %lf %lf %d", &n, &l, &v1, &v2, &k);
  double L = 0;
  p = n / k;
  if ((n % k) > 0) p++;
  L = l / (p * v2 - (v2 - v1) / (v2 + v1) * v2 * (p - 1));
  printf("%.7f\n", (l - v2 * L) / v1 + L);
  return 0;
}
