#include <bits/stdc++.h>
using namespace std;
double v1, v2, l;
int n, k;
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  int tang = (n + k - 1) / k;
  double t1 = 2 * v2 / (v1 + v2) * (tang - 1);
  double tt = t1;
  double t2 = l / (t1 * v1 + v2);
  printf("%.6lf\n", t2 + t2 * tt);
}
