#include <bits/stdc++.h>
using namespace std;
int n, l, v1, v2, k;
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  double lo = 0, hi = l, mid;
  int tot = (n + k - 1) / k;
  for (int times = 0; times < (int)(200); ++times) {
    mid = 0.5 * (lo + hi);
    double delta = mid / v2 * v1;
    delta += (mid - delta) / (v1 + v2) * v1;
    double dist = delta * (tot - 1) + mid;
    if (dist > l) {
      hi = mid;
    } else {
      lo = mid;
    }
  }
  printf("%.12f\n", lo / v2 + (l - lo) / v1);
  return 0;
}
