#include <bits/stdc++.h>
using namespace std;
int main() {
  double l, v1, v2, t1, t2, l2;
  int n, k;
  while (~scanf("%d%lf%lf%lf%d", &n, &l, &v1, &v2, &k)) {
    int ti = ceil((double)n / k);
    if (ti == 1) {
      printf("%.12f\n", (double)l / v2);
      continue;
    }
    ti--;
    l2 = (l * (v1 + v2) * v2) / (ti * 2 * v1 * v2 + v2 * (v1 + v2));
    t2 = l2 / v2;
    t1 = (l - l2) / v1;
    printf("%.12f\n", (double)t1 + t2);
  }
  return 0;
}
