#include <bits/stdc++.h>
int main() {
  int n, l, v1, v2, k;
  scanf("%d%d%d%d%d", &n, &l, &v1, &v2, &k);
  double res = 0;
  int cnt;
  if (n % k == 0)
    cnt = n / k;
  else
    cnt = n / k + 1;
  double up = (double)(v1 + v2) * l;
  double down = (double)((2 * (cnt - 1) + 1) * v1 + v2);
  double l1 = (double)up / down;
  res = (l - l1) / (double)v1 + l1 / (double)v2;
  printf("%.12f\n", res);
}
