#include <bits/stdc++.h>
using namespace std;
int n, k, m;
double l, v1, v2, t1, t2;
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  m = n / k;
  if (n % k != 0) m++;
  t1 = l * (1 + v1 / v2) / (v1 * (2 * m - 1) + v2);
  if (m == 1)
    t2 = 0;
  else
    t2 = (m * t1 - l / v2);
  printf("%lf\n", m * t1 + t2);
  return 0;
}
