#include <bits/stdc++.h>
using namespace std;
const int maxn = 10010;
int main() {
  int n, k;
  double l, v1, v2;
  scanf("%d%lf%lf%lf%d", &n, &l, &v1, &v2, &k);
  int num = n / k + (n % k ? 1 : 0);
  double up = (v1 + v2) * l;
  double down = 2.0 * v1 * (num - 1) + v1 + v2;
  double l1 = up / down;
  double ans = (l - l1) / v1 + l1 / v2;
  printf("%.7lf\n", ans);
  return 0;
}
