#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, l, v1, v2, k;
  scanf("%d %d %d %d %d", &n, &l, &v1, &v2, &k);
  double s = 0.0, e = 0.0 + l, optimal = 0.0 + l;
  int cnt = (n + k - 1) / k;
  while (e - s > 1e-9) {
    double l2 = (s + e) / 2.0;
    double x = (l2 * (v2 - v1)) / (0.0 + v1 + v2);
    double b_time = (l2 * cnt + (cnt - 1) * x) / v2;
    double p_time = (l2 / v2) + ((l - l2) / v1);
    if (b_time <= (p_time + 1e-9)) {
      optimal = p_time;
      s = l2;
    } else {
      e = l2;
    }
  }
  printf("%.9f\n", optimal);
  return 0;
}
